Printed I was in a room that was like covet. Ackee could see like this one and it was like, this is a big roof. They run a model in each room and the way that I found is, if it affects every single person all about This is 


So, you are 


You are? Yeah, that's me. I'm not sure she. 


I'm doing great. How are you? 


Here. 


And I thought you were 


There's seven eight people in the class. 


What, you know, just 


Convenient. 


More like I miss being 10,000 dollars to remove lady. Yeah. So like this I know that I'm paying for grad school or get that 10,000 dollars. So and I got that thing. 


People right. 


What do you do? 


People working. And, 


You know, you didn't know anybody. 


Tweet, I capture you salaries or hourly. 


Need but anyone's like do you want to be broke up with broke recommended you? It was like fuck. And then the classic minds I would recommend him like don't take it as like a you need to take care of that. 


Annoying like this. So, and then maybe he said my daughter, like the whole kind of glass like, Like my daughter. 


The ET193. 


Another glass. 


I don't know. It's a nature. 


Hello. 


Everybody's wild. Hopefully. 


That's coming to teach us. 


So, if you don't understand me because I have a naturally muffled voice, just has the question. 


Think of that, that work. 


All right. So welcome something. Everybody's here. 


So this this course, is all fashion, the kitchen and the remote winds and seems. So we're letting, you know, first is 580 South a specific. A substitute of this is believed hormone treatment of supple. So it's not a traditional software engineering course. It's rather than looks at the form of frameworks that people understand about this office specifications. 


And to give you software in general, the backward sophisticated level, then typically doing, you know, every day that drugs. So my name is Devin Roman, Hello by Dr. Roman and my history. Basically, I brought in here can be United States for schooling and from a profile dance. And then after that, I went to Washington University in St. 


Louis. I was there and I think that and yeah, and as the garbage 


About Well that leadership doesn't have more power to save things out. So, anyways, I went to Washington University and India and I think we have the beginning. And now I'm out of administ. And, you know, professor in bed science, I teach the software engineering, capstone course, and I think mobile computing and soft the city. 


Normal course, that kids with each other, things like University. And the Department wanted me to and he buys CS531, which is a job at Java program so I need that I definitely normally not. 


So let's and stick it kind of systematic. So, you understand why In terms of teaching study what I teach here, but solve my career. Basically, I probably introduce the 21st of 2019 course in the country and pro PhD is attention. Is a false, the country. And I also talked on currency all about computing and occasionally, other things that there's something engineering is my the planting study. 


We're teach house I've done it last year teach and escalate from Farmington. Beginning to something architecture, those of the two main states in my industrial teaching, and done, generally how to use the materials on the classroom in the industry. Teach industry, they would pay me to revise the materials improved them. 


Then I'll bring them back in the class after we test them on projects and depending 


I have not done. That's a training calendar since that he came. I've got to come back to it, But I have done consulting and I continue. I started, I mean, I told you it's going today and making friends and dynamics for government, that's nothing and they're on Facebook out. 


Then I'm shifted to Emerson Electric in for many, many, many, many, many years. 


Any down a work on physically security or satellite systems, how to kind of things related to kind of swarms of people's work together specific tests. It was a research. Most I mean, I think So, when I am you do the research with the money is? So I did have one kind of stuff. 


So I have I was involved in the database research of any early on. But the broader and the problem of the very first concurrency condition algorithms for techniques at the point, were we didn't even know what men to have a correct. Implementation of a database people are discussing that academically you figure out what used to be correct when you go to the student system. 


And today, we understand it, emotional serializable, transactions. And that's what the definition of correctness is that constant was just involving. So it's part of the groups in countries that are developing their algorithms which is for the very first operation to work on reduce computerization was defense mapping agency. Just said one, I would like you to the population, so I did that. 


So we did things like recognizing objects on the ground from the air and then I done. Even the artificial little bit feel this eye solutions to hidden in the surface and innovation. We had a very first think there was a highlight processing in graphics, We are not recognized because it's very early, but it's interesting that one of my colleagues son who went to the talk group in graphics called us back and said, mom Then guys, they don't the first work even though many people know that. 


The but most I mean again the quarter might research has been software. Engineering, I'm focused on formals from the methods distributed algorithms and those all that fit into this their class For the last. 


So I'm a people interested in environments where there is, there's no internet. Everything is feared to be here and everything moves and not only physical mobility work, laptops, iPads or different moving. And also, you know, the code itself moves from one place to another. So this is those physical mobility and in that area. 


I mean, we developed, I mean, many many other reasons I in their in their field and we build a productive. Interesting. Demo instance, we here we work with medical school. Washington University is one of the domin. 


26 model, drives meters. Some corpus medical school to monitor patients in the cardiology. So basically we put about a similar about computers the radio, they put flags into the walls to the pretty trust me the signal and then it make sure that the patients are from them. Okay. And the idea was that at some point we add some logic. 


So, when we see the people are not doing well, we can figure out the demo bring well, and send somebody to help them because it's not a typical in the hospital that they eight hours. When you start not feeling well, I think eight hours till the doctor sees many people died in those eight hours. 


So clearly then, you know, it was we work through the Boeing security to secure. The shipping is affected networking and same, agents more specifically on containers volume of flowering for security reasons. For maybe they needed another discover the trucks to close WordPress. Navy basically taking a network that originally assumed to be monitoring like that and then he purposing it to monitor fire the forest. 


And so basically we have this net worth different more sensors and then we inject an agent and the agent to move around and network and to provide that would close itself like a violence all around the fire. And then sending the days and saying, here's where the fire is the firemen. 


The other interesting deal was I did one of the very first don't have here. A few cameras first time. I started with cameras, probably about 30 years know on four vehicles, experimental vehicles. So we worked with them to use wireless communication negotiate, passing, through internet interceptions. So basically, the most stop sign. 


They're not trying to apply the car has come and one slow down wants to be dark. Well, the GPS was not part. So we actually ended up having to put the bumper and our software started with about 50 meters above. Now, the same. I mean the GPS has been reclassified about it's on the description and encryption has been moved. 


So now we can convince you but it's not that kind of thing that you know you can Comment work is on an account of things but basically trying to get personalized interactions between IOT and people. So we basically would like to be able to our joke is that despite having this IRK of watermen, which many people think it's a hangman, and three years of trillions of dollars market, We come to another life and it's a joke, but it's actually true. 


I can have a nap which comes on the light in this room because I know that they want to like, and they recognize it. But if I go to your place for dinner, I couldn't remember because it's totally different place. And you know maybe maybe you speak a 40 language and the name sings around million so your name sings using the language. 


So when I come in, I mean why even you might see the least, I don't know the sub lights or microwaves. So so, you know it's very important to be able to be able to work from one setting to another, which means move away without actually having to change it apps every place in them. 


And that's kind of the, you know, the Holy Grail of what we are trying to do, when our research grant. It's a population, the University of 


Still learn quietly. Like I said, so this kind of research portfolio. Let's see what else. I put a lot of advantages on and that particular, I think particularly interested in the darkness director of the dark. Then I went ahead department program. So, most of my students that advice are actually I'm very too. 


The environment. And Somebody's present I've done. But most of the students talk close to plenty and many of them want to operate. So I have former students. Who are? I mean with the department chair, it's going to New York. Don't want these 20 and Italy. Someone now it's a department, chair temple and associate team that for professor and in Boston. 


So, it's been a very, very rewarding, the house of student and success, with their own videos. And one of the recent conferences, as in five or six people in the leadership group were life re program. So if you have interest in the United program, how many creative program, I mean I will try to play. 


I'm very, very passionate about can contingent life, and can also 


To get to where scientifically. The better decisions we can make in the in the long run. 


Population has a voice in a lot of policy issues in legal indirectly and those qualific scientific knowledge. And what you learned in my community program, you don't have good text, you can see a problem and you understand it and you understand what it is. Interesting problem. And also you see a solution and then you pass judgment because you have enough enough experience and understanding doctors would make those decisions about you know, what is a good solution. 


So that's kind of most mostly about about me. So let's turn the table and you tell me something about yourself. So I have a list of students who should be in the class so that I have. So I'm going to call on the list. So, Jose Carlos. Hey, hello. 


There was something. I'm telling, obviously, what program are you in? And maybe when went went to school before or the I mean, if you are a foreign student, what do you have? Or if you have a unusual hobby, you know, something that would help us remember you, okay? Okay, where hello, all my name is Jose. 


I'm come from Peru. I did the undergraduate in informative engineer is the way we call them and I'm actually in the master of science in computer mastering computer science there and this is my exchange semester here. Yeah, I'm going to change and I'm planning to finish that in December and I'm also planning to apply to the PhD here. 


That's what I'm planning on. Well, my hobbies I say that I like climbing. Not that true and climb little bit. But I I would like to be as Tom Cruise another way. But yeah, that's nice. Yeah. And I am open. Yeah. Okay. Thankfully line. That was taken graduate students here and the computer science and what undergrad here. 


Interesting fact, I guess sleep 12 hours a day. I was like, on everyone. Hobbies don't have a lot, they don't feel like they're three times. They have a job as well and school that grew up sleeping full-time. Now I am a TA for free 25. My favorite class. Yeah let me just guessing that got any cool don't ever outside. 


Don't know. Well, yeah, my wife and his meeting because I can't sleep. I can go back and compete in Miami tonight. It's a country. All right, so let's say, yeah, I'm not here. This student here, and it's my second semester, and I want to do this, maybe on cloud computing. 


But yes, and I think that's all. Sneaker sweet. Samita. Please don't correct my hair. My pronunciation. It's gonna be. I don't make everything special. Thanks. But yeah, my in my family. Nobody pronounces my name, right? So you have to have an understanding here. I've been. 


And coming back hobby. I like to watch the things that she has said. Let's see. Danielle, yeah. I'm Danielle. I'm is my last semester. I worked as an intern at Sandia last right now with the center of the cyber defenses. I'm interested in specifically network security, which standardization 5620. 


Yeah. So our 36.9 is designed, so I guess. So that's kind of what I'm doing and my hobbies are also smoothly and Netflix somewhere. What do you plan to do after the? So hopefully that's kind of the plan. It's to get a maybe not a research though, but I haven't really done research. 


So kind of looking into that but it's getting sandya droppers. And really, anybody knows me. I'm not allowed to send email anymore. It's so special. My name is Marie Martinez. I am a HD student in Drug This group. I am doing my research on network security at the AI more offensively. 


I need to do non-scripted attacks against South Parks and Marines. So, I've been personally that, in my spare time on the scuba diving structure and I work it, these system support group up on the third floor, Of course. So her selling jobs in St. Louis were much of my life near some ways. 


They are the volunteer landm and who stole actually used them for training for be diving because those mines are so big and are completely filled with water. They're very dangerous but in the middle of Missouri doing dividing preparation for ocean is just Christopher me and I work at Indianapolis and Laboratories full time is a R&D computer scientist, micro focus is on remote sensing perception and it's gonna take picture what's in it. 


Where is it, how scared should I be of it? And currently with PhD program here and focus on computer vision and target replications today who you are working with. I'm currently I'm working with Dr. William. Mini Germany. 


Need a 


Word person. 


So, you raise birds or they'll do good. Watch. So you're not part of that conspiracy that the common system, We're in their government development, but they're real nice but that's a charge in the night. What it says, that's an official they actually blown the flag of the San Luis Cardinals and they demonstrated in front of Twitter for abusing birth. 


Okay? Soji. Yeah. But don't tell us something about yourself. What what I was studying would come from any interesting parties. Your, my name is. So this is my second semester of the CS student. I have background in mechanical. So last message, I just pray around for the class. And so this is this mister officially I'm taking graduate level process. 


I may need some help from you. 


Okay. Now, So I'm Matt. I am a. This is my second semester as a master student UNM work at the labs work for two departments. I work for the robotics vehicle range and for the biological and chemical sensors divisions. In my free time, I've currently gotten into playing disc golf that by the airport. 


Yeah. Okay sure, I'm Sean, Tim. I'm also a graduate student here. I did my undergraduate work here as well. So pretty normal. I work at the labs as well. So a lot of us that seems like every class of men is always a handful of people who work for the last. 


So it's nice to see you guys and something interesting. I captain the ultimate fishby team here. So a lot of my friends, always laughing because I always have a shirt related to ultimate in some form, but, yeah. Nice to meet you guys. Very swimming. I'm an international. I'm still in the process of getting registered my classes. 


But yeah, my name is me. I'm from Nigeria. A patient student. This is my beginning of seven year puppies and adult activities, music. Movies shows I'm interested in doing research in network security. Yeah, so you just came to your name or you've been in, you know, I've been just in the process of 


All right. Well, thank you. 


Now one of the things I'm going to send you an email, when things I like you to do is send me a passport type of picture in your name in your email So I can then sample them in a table and two years from now. When you come back and say, would you give me a lot of reference? 


I'll say and we're sitting at the role on the right. Yeah. Okay, So no. So I think would help you also learn the names. And In particular, this is mass, I mean, as I thought this was for Engineering class and 40 students for the first time, I mean, I'm not very good at these names. 


So, I had to work a lot harder than other people, but I mean practically, I didn't somewhere that strain that didn't have a mask. And not saying just thinking of my class. So anyway, okay. So I'd have to because these are very means, of course, in many, many respects, I'm going to talk about the course and content, but I mean, there's a spot. 


Number one, is that there is no testing. I don't believe in testing I didn't even learning number two. They're very important is particularly important. You can go in and instruct a basically guarantees that's going to work with you. Whatever it takes for you to get a list of be hopefully a name. 


So I already saw another MTAs. I don't use DAs I mean I have an appointment in life. What I have accomplished so many things in the children to talk into African conferences. I traveled over the woman's own So I can make my own decisions. And so my decision is that you come first. 


So I'm available to work with you. The course is conceptually very difficult. It's their all kind of subtle scenes. It's a different way of looking at the world but I had to and to be able to succeed in this course. Now I might be going to get all this force going to be different from different people. 


It matters a lot, you know, your background because you are building one paragon that you have you're going to learn another thing. But you know, different people going to learn different things and that's okay. So the important thing is that you have to steal the class. If you're singing an interesting feeling that, you know, process, beginning to difficult, something talk to me first before you kind of disappear. 


Let's see what the problem is and see how we can get more help, but health is not an issue. I mean, there's no other class where you can get as many much contact time as you as a. And you guys verify that the answer is emails and like, five minutes often, it's real very fast. 


So so it's really, I'm here for you, but it's not an easy course. You have normal done this sense and not many people do it. So you're gonna get skills that are unique in the country and you don't know, when you're gonna need it of several of you use the work security. 


What I work in cyber security and FRL. And one of the things I feel involved is exactly using this, kind of knowledge and this kind of mathematics. So thinking for disappointment and nothing people can do that, I'll give you a little bit more value about, you know about. So that's one thing you really want to get support is not going to be easy, but you are notice stressed by test the greatest based on hormones. 


There's a assignment every week. If you have problems, you contact me. We have tried to help you solve the problems. And I try to adapt my thinking to your pers low kind of different with different. Yes. And and like I said, no, I'm trying to ensure that Justin successfully, don't care how much time it takes. 


Like I said every you know home or something, all the lecturers are I mean they just have type and they meet those in PDFs someday on radio and I'm there I'll be using mostly and also I I'm going to try to balance between lecture time and actually working together on problems and solving problems together but my current plan and may change maybe this after reacting real time to. 


What's happening? And my current plan is basically one week is mostly lecture besides decided at the end. The next week is probably most lean exercises in but we work together to see how housing but it is different. It is new. It is something that you have not seen and going to be unique in many respects. 


The other thing is that one commented one video. The one coming I get is often is why use this particular conversation system? You want to today consolidate? 


And please ask questions But I'm using a very big limitation system. It's only appears in one book and probably thousand articles. It's not a programming language that you have a use that is a tool for you to learn how to think about compliance systems about specifications. And once you get that thinking in didn't apply causing rather situations. 


So, how important things in this course? We are focusing on formal treatment of the problem and the reason is that formal treatment will be codified. Our understanding of. So you all heard about the possibility results but that really, it's a very fundamental not relevant to this club, but it's a very fundamental concept of how we think about the harborises and decide that we understand that and understand the limits of what we can do and prevent you from trying to solve problems with that unsolubility spot. 


So that's why it's really, you know, basically it creates a foundation from which we build things and people understand the portable methods also shape our thinking. That's very important for me, you know, the gonna use this particular programming language. If you can call it programming circular conversation, you know, I mean use it in your email practical, but the ideas, the concepts that you're going to learn through it, then that universe can be applied anywhere. 


Many situations. Now, some of the names, you know, may not be applied and cutting jobs by jobs. Change technology changes. I remember when we were fighting which hand, you know, hundred permission and regular commission. That was not very I mean nobody could solve the problem rec. Well, I use no taken Nemo right now. 


My writing is pretty hard. So by the way, if by writing on the board it generates stop we're not going to be as bad as my parents. What's my parents professional medical school and don't like doctors. So one day we, when I first came to US we've correspond every week I could not read a word or a sentence, I could only be the common paragraph, the women. 


And they know I'm not that but by the generated. So kind of love my son. So yeah. Driving information I use now or no taker and is buying writing, it conversed, text was very feeling things. It's amazing. You know, we talked to our Alexa and Siri and we talked to all these automated annoying response, you know, the phone system, they understand I have a 40 accent and the muscles and they understand me, you know, my car understands me intense. 


It's amazing. So you see, technology changes things about impossible. Today they come a lot of this formal methods that today, and look to you like that. So unusual. So different, so special, maybe come and maybe not in the way people thought about, but in different words. So, for instance, I spend the mini semantical and in the run in Germany and the group was working with a specialized in model checking. 


I don't check in with a credit card, properties of products. Now, they were very hard properties of real problems. Not abstract notation real programs keywords and they developed techniques to be able to actually explore the state space of the program. In a very efficient way. And I was a memory of us if you but they could do it. 


They were doing for a small subway station about but that they're not changes. I mean your mind might be given tools and five years from now that use model. Checking, I'm not checking the way in which basically the better image because the question about the program and the system, analyzes a code to answer your question. 


So you could say is it possible that this program would ever? You know, turn off the radio on the salary. That's that question. And then we'll analyze a code and come back and say, I don't know, because something's I'm not solving right? So why not, we're not gonna remember information or when they say definitely can. 


And here is a module, the line of code that would do that would turn on the satellite at the rate of this for me to ask that question. I need to understand logic most of the F. I mean, of course, it was all this research in building all this technology, but you also had to know how to ask the question. 


And if you do not understand the body, which is related to what we're doing between these class, people, not submission. So you see how stuff that you may be doing in this class, you may not be able to to your pain the job today. Tomorrow. Make sure I'll be and you will beat that head on the crowd because how many people are going to know how to think about component systems are from a way. 


So keep that in mind, it's the future. So the skills that you learn in this class, you know, in limited fashion will be applicable to systems that you're working on. Even, so give you one example, there's a concept of embarrassed Italian properties their properties at the lowest true. It's a very powerful concept that when you deal with concurrent systems, if you know how to think about that, you know, all of a sudden, you can look at it problem in ways that you haven't, you know, other because you have a way of speaking. 


That asks, the last question. And I question that I was some because I think that's how he knows in the roof, that was them working on YouTube and GPS on the other side of system. 


So that's what we're working on in the next and important thinking that an opportunity process and how you find people that relationship. And so we are distilled what will, why would you like the foundation and still maintain cons? And in the middle of that, one of the values technical since. 


Oh my God. No, I know why our systems are failing in the field. Didn't feel very often once a year and someone had to go and press a button. And he said the system, but they would failing because never, they never were never able to deal with concurrency and think precisely about that interaction that code. 


I don't know what the copay is, but I'm going to be talking about this online, so good. Then the direction probably is limited to about 10:49, okay? I cannot lie spent my delights by him, but I had to have the way of thinking that allows me to do that analysis. 


And most people know I was involved in another project, but I think that dealing with the handbrake electronic, handbrake for the Porsche. And the contract said the two microprocessors involved in pressing. That button great for him. I don't think I've applied at 80 miles an hour. You know, I have mother life So they were all kind of safety concerns and stuff like that. 


And you know how do you apply it when in an assist mode? So you are rolling backwards in the heels but you want to get help but you don't want to lock the car. So there was a, we should say. But anyway, the contract said they had to formally prove that that their software is correct. 


You know where improvement helping all these lights of coach all see written by people that learn program. Another state and never have imaginable. Just no one like that's been about how many toolsophisticate was modular on the other hand if they actually recognize that that was a critical design constraint. 


It was all, I mean, I was able to basically receive the design the system with basically controller, which was the final state controller, small number of states. I can exhaustive check which no machines. I don't need the machine. I can be by hand because there are so few things enough, of course, there are assumptions about the rest of the system and you always have to make assumptions. 


But, you know, basically, I could do the pool within 10 minutes talking about. Think about that, I don't know what happened to the content, some of the people from problems that are very impossible countries. So, okay. So this has decided kind of the spreads in my mind that, you know, molding my, everything about these course. 


And I'll try to basically convince you. That this is that right way. So let's look at some of the contents. Well, we're going to talk about some cars. Every system that exists today is concord, there are no significance and my. So and things, if any famous could be a science-based types. 


And I'm hope and in there from your science program. First year, students were not allowed to code. They had to prove programs correct and only after the think about programs, you know, from a mathematical experience, and it's really extreme. But it's interesting approach to shows that the physical importance, have a great meeting somebody about, you know, maybe what we should treat students programming, we should teach. 


And after 40 years, put a footnotes, as, you know, by the way, they are such thing as sequential programs, but it's concurrency. That's different. And so we want to focus very much on what it used to. We have an consistent levels of characterity how we think about them from modeling, all the way from the register up to a large about. 


We're going to talk about people who want to talk about the currency, we've got to make to have some something to work with. So, you know, other reasons we find our knowledge at useful because you can use them in settings that have nothing to do with this course. And hopefully you're developing your skills and thinking about ourisms and developing organisms. 


So we're going to look at how many of basically fundamental that have been studied expensive because nothing entertaining just didn't function on the medical staff and we're going to use them as a way to to learn the concepts practice of skills. Test our mutations. You also going to learn about how to specify sales formula and then what they hundred back in your job. 


But if you have a, if you're not going to be another protocol, you know, specified for me, I been writing 


And this will come and I didn't know something was telling us. So that's why the formal thinking tells me. Figure out what the problems I want to hear. Is they've been published in algorithms and being studied by the top minds in the world. And then somebody discovered a vanilla Covenants is identical compatible with particularly so skills and specifying formally. 


So you can think about one of these properties and then, you know, using semi-formal thinking and making form of thinking to actually test your hypotheses effective. Some, we are going to use a particular style of verification. Is conversational because it is it's easier to think about it in terms of properties of the state of the system. 


Yeah. Like I said showing that many other models, but I chose the model that I really particularly easy to transition to beyond systems and the employment. You're going to do a little bit of programming innovation, and I see starting the specification and doesn't actually gradually generate a program. That's a holy grail, scientists and studies. 


It's very difficult to do. It's nice to understand a little bit, but it's still a skillet At some point. Let them of course. So we're going to start with, you know, small problems, trigger algorithms, more than four and more. At some point, we actually pronounce that question. Okay, we learned on this techniques. 


Can for the real. So we're actually going to do that about, take some real distance, small going to look at how we can do a pharmacistification for. So we actually going to attract people whose ourselves address. Our student respect is going to apply to the world problems. Having your company may not allow you to do it because they don't understand it because, you know, whatever, okay, no problem that culture but you can understand the skills in that country for another and people have found is going to be a little bit of mobility. 


That's very end of this course. But any decrement on the okay, the syllabus. It's not of. 


There's a difference. There is a reference book. A mission is possible everything that you needed across how we provided you. Once you have the book going on Amazon and getting used is nothing but anymore. I can reprint it or I could reprint it for the class. But because of course to 100 bucks to get the copies from doesn't make any 10 bucks. 


Any questions about you can see that I'm very passionate about. 


Okay, let's look at someone organization nations. I've mentioned all it is with your number to give you, thank you. So, the class involved in some way. And as often as this composite, you cannot miss class. Unless you tell me the best class and only for an emergency situation, not 


On assignments, might be submitted. Give me one assignment. You get enough. So what Asana said we can have time If there if you needed delay. We really have to negotiate that with me. You have to meet every time. So of tests but the Simon 7:40 in Jefferson Montana. One of the submitting our time also is because the fact that we are going to discuss and class the solution because some few say well I do next week no because the rest of the class now has to be for the sufferer. 


So Trump don't have any assignments. Generally the assignment of even Wednesday, that they have the class, and that the answers are due the following Tuesday meetings. So, when I get up in the morning, you know, Wednesday morning I guess have a great day because I have a great day so I don't, you know, I do have other obligations, I'm going to configurations, you know, I made research meetings, I made fundamental meetings, and, you know, other stuff. 


So why I really need to and try to reserve this in place. More grading is, I need to 


You're gonna get a better experience for this tragedy. Particip God's equations. If you post questions, we just had like anxious. We look at the audience and I say a board, you are good. I get what you talking. You know, I can work on it for another hour and still sleep at same time. 


On the other hand, if I see the two and try responding, you know, all of a sudden that given different lecture, I gave the same talk in three different places in Japan, we even spent over the week, same set of slides, horrible, in my students will happen to viewers, which is terrible because I don't like to have the same people. 


This means at the same time, right? But they send it. The answer was not the same job but since slides but they've done listed different dogs and that was because of the different audiences in the reality and I think no one knows what to do with makes. 


Some of you haven't come to me in this. What's my grade in the course? Answer number one answer is that you better get a name this course if you're not getting an age because you didn't get enough help. I mean very simple. No, you're gonna get 100 points when it means whatever side. 


And basically if you want to say, okay what I do the course. Now, just look at the please. For a 95 percentile and 5 percent. And for me they 85% that's probably to be 75%. Let's see. And I don't want you to be the same age, and you better take your coming. 


I'm sure there will be a assignments. What are you gonna say? I mean if some of us have a family and they give you laid you start late, you don't get enough help. And but that's has to be now a trigger. Okay, I mean not to get any hundred next time so make sure you get from King Israel. 


Okay. So here, all the help that you to really, I'm trying to do you look people in the class to work together and the next and I'm very happy to entertain any teams of true working on assignments as well because there's a team. There's a learning that takes place between two people problem. 


So I'm very well very open. If you're saying know somebody and you want to work with somebody to what set of emails to that's why it's me and you get the same grade that those people can say. On the same time, I have to warn you if I sense that one person is not really carrying the load. 


Oh, no. Just play the team or you can do it yourself, don't it? You don't need my intervention. Do we not work? Because we are thinking may not work because your schedules are different. The many reasons for them are or sending different mechanical the most challenging thing. And I had a former student of my group tourism, which is associated with your stand where I was on a grand. 


And so, she actually flew in, and spent the last three days working on thinking about, and my wife was commenting. 


But she was my student. So we've been working together for about 20 years, Want to know. So we know how we think they said very easy for us to interrupt The various very easy to say this is concept. I don't I don't think anybody's going to buy this or there's something here that has really good. 


I have an idea what it is. I mean we can be honest with each other so we're thinking you know it's difficult to match it sometimes but that can be able to helpful and also a challenge. Now, if you get an assignment and you need to talk about the sum and talk to me because a group of two, you can talk to each other, but you cannot talk across groups, haven't even at the high level, you know, does this is a similar to that main as always? 


Yeah, but in the details of solution have learning personally conduct. 


Okay. Now, your many years So I do it again. Now in the past, I have found a helpful to have the Slack channel where students can ask questions and and things like that. It would you probably know that because you stopped your solutions does not spread in the class? 


And so that's I don't do that. So that's how you stick only on these and then like I said we discuss a solutions in class actually take your word because and then I'll show how I would have thought about the problem and to be honest sometimes it's so funny, we come up with ideas but even I may have stopped born. 


You may keep on something that is new. And I the class is very long and they're going to be like an interception. Okay, so that was a question for you, so doing one. So, you two options. What is it? Just type of glass for the older. But you guys tell me what you want, I can go either way last month, I must semester doesn't run a course. 


Most students wanted to stay continuous but do remember people that basically said, you know, ideally I need a break. So you guys tell me and like, do that, 


Okay, It's not the one. Who's rich? 


I can't remember the board because I don't have a pair. 


Okay. Couple. We need to be efficient communication. So, there is, I have a lot of things to do in my life emergency room colleagues that. So I need to go to, you know, first first priority and whenever possible. So, when we talk about email communication, 


If you understand me, email about the course bracket CS and all capitals space, find 80, no space bracket, space subject. I can sort my emails. I cannot give you my password. For example, is not. I know I needed a patient to national conference. We had one email messages and they had to be responded, Okay? 


So that's why I finally extended. Well, I'm gonna he filed, I go for this and I immediately pick up and this is also a little extensive. So that's one thing. The answering is that you're going to say honors assignments. So subject CS 590 and then coverage governor. So please keep pay attention to the capitalization. 


That interests the space, a short thing does not work machine. Sorting does not work and rules machine rules. Don't work. If you change, you know, sense, so you put an agent, you know, lowercase h, you know, that's throwing those things up. So anyway so then you have the number because to 010.03 and so on and then we have the thing, what did you think? 


Like in the back. So first time is going to homework. You write the thing here. 0 0, 7 3. I never had a collision with anything. There is a traditional telling and you change it, Okay? But that's the way I want to see all the homework assignments in terms of the subject matter. 


Now their file, its PDF something. Here file, the side effects. And here, make sure when we use PDF that you don't have scan stuff. I cannot my fast cancer. So if you, you know, it brings your word file and then you scan it and then I get a picture. 


I cannot mark that up all the feedback. I'm giving you is through annotations on the period so I have not gotten opinion. That's the way it works. Now if you have a little picture that you haven't finished yet, doing it in PowerPoint or something like that and it wants some sketch, you know, just to get that picture and text underneath it, so pay, you know for drugs but make sure that it's right for you. 


And then the the bombing spaces need to be HW again. 15 number. 


A nice. That's the way the product will be made. If you don't know, if you don't like a blank here, you know, again, it gets sorting its messed up stuff So that's a nail of the file. Now, you are going to send me possibly questions about the hormone, So you may do part of the homework and send me an even gonna send me a, you know, let's say video this part of the hormone. 


So, I mean, first of all, high respond, very fast, the shorter, the question, the faster I respond, and more detailed, more attention again. So so that if you have a certification question, don't send me an entire home workout or one with a question next. But if water interests and that, that answer to that question. 


Now if you work part of the homework, then have some issues. And so what I think is going this way, but I think it's important. That's okay. Let me send in the PDF file and then the US dollar and in conversion 5 together, why the version number? When you send me your email because this video. 


First of all, I know that this is not, you know, just a two hours before the deadline you send me a file and even though this is actually your official submission and you know or something that you found on them to help you. Okay? All right. So so that helps me, make sure I don't get confused between official submission and something and draft which on YouTube. 


The example, the way I'm going to work is that I look for your email. I put the file out, I might get up, send it back to you, and that's right in the trash. So if you keep on sending me the same file. Name file name. I can go back to the history, but if there are different versions and I need to understand what I thought, I really told you thought to fix this, go back to my trash, I open the fire and say, yeah, I told them to fix this. 


Why didn't fit? Okay so the last me to keep track you know go back to previous versions. Okay. So are these ideas roaming in Rosemark? Just use it to be I or that it's a couple small and so like the B to. Okay, guys, that was just over the eye or a one that you were running, wasn't? 


I not using dumb question, We start with version zero or person. Well just you think you're member version so I can turn but it was nice here. This mean, I noticed this video which allows me to be more responsive and allows me not to make. I got to, I got an email from one of my colleagues had to do is update station. 


I was supposed to know a whole bunch of work, you know, I thought I did on the work and I made a mistake. I forgot to attach three points. Okay, she had the text there but the message was this long. The text about those files was about here and it sounds really quickly because I was trying to be responsive. 


I wanted to be the first one to deliver an answer and I missed episode. So I tried to be efficient. 


Anything. I have no questions. Do you want to take a break now? 


Okay. 


And remind me if I don't even break any money. When you see and not translate. 


Don't across. 


I don't have my my market but I don't have any name my own except so I hope they always have my eraser. So you're doing, oh god, what else are you taking the semester? Computer replication, and computer networks. Cool. 


What are you? I'm taking computational geometry databases. I'll tell that. And this complex systems in this one although taking four classes. Oh fault. Yeah. Okay that's third one. Again complex adaptive systems. Oh please smell any Moses. Oh almost. Yeah. But I think bring my wife relative says okay. 


Can be removed. 


Are you teaching anything else so semester, because 


How long is 21 as a for me? The false semester is the one very difficult. I can do more recent in the spring because I mean the gratitude grandpa or something. But something engineering class that is that concern is real time teaching. And realtor not grading but marking down three fours. 


Every single week at least 834 while I get 8 management reports and then each particular reports every single week and I need to schedule my in my time for me. 


That's, that's very time. And also you know sometimes you take chances I use as a I believe, okay studies, very simple problem in a more complicated problem this way they can twice 


I decided to use a drone. 


19. I fell in class see their failed and because you're none of us would be written. Any code for drones and design software programs. I had some exposure because consulting. But one problem, they messed up in a different way and I expected. So we had a design and the code had no relation. 


I mean, for me in the software engineering, no sense in pilot team and league, negotiating design, and those people and language, rich, and sensors, on that particular, 


Would, and that should like, hear my easier highlight easier. And the product, the basically program, so many. I mean, the design hand and altimeter called there is an object and alternatives was called out and to methods, they're designed didn't have any other. And you have no know what the implement They were, there is crazy. 


And I got my work. I feel like it takes a lot of meetings, and a lot of accountability to keep software on track at times. It seems like people really like to something. I'm gonna get like a flow state bell, just kind of go off on their own and that really all lived with the design anymore. 


Yeah. Well, that mean part of it is most companies are not designed here and how the document is now. I mean I'm working people really. There's no no design document how they can manage that company plan. It's amazing. 


And I like to to test the system demand system. I'm gonna get. And also, if you have, if you're gonna the subcontract parts of it, if you don't have the design and fully specify there, you're going to get junk that you can easily. We had we had one case where we the governance some contracting. 


So there was female of Ind and their labor rate was quarter then the medical library and but they didn't understand that. So, you get stuff that really was totally unusable and the number of hours were higher. So in the end you got something that was not useful. 


What's the main encounter? Particularly what I work with only work with other teams and you don't really have a background necessarily and software engineering, but a heavy background producer is I encounter a lot of sentiment like, we don't have time to do a design document, because we have to do all the research. 


These stuff this is just researching code, and which is a defensible argument, I think. But with it, when that research system, inevitably turns into a production system, now we have a system that was that was organically grown and, and the annatto mess because there's no agreement on structure or, or how can she be designed. 


And so I understand where they're coming from is that you're asking us to apply and design what we don't even know with it answers should look like because we're doing research. But by the time you get to production we'll clearly the time for design with some kind of. Yeah. 


Have you seen this? However, okay. No, getting Michael here. I mean my students built a lot of systems and but we basically and we know how to fly very sophisticated of engineering cool because you're still always system to build them once to demonstrate you know, an algorithm to demonstrate some ideas and then I didn't expect anybody else to use them. 


Now, they were something that we experience other people, okay? So we built the line leader mobile environment source. I mean, that is carefully designed because we knew that was you, but you have to know is a throwaway software is not the other thing that you have to know how even in research about how it seems when I go you want stability in the interf. 


So you try to push all the research into one area here. You don't know what but you have all this code that you support them. And well, then we want that code basically very where, at least this thing is that build something and saying, build some program, and you build it on top of this, okay? 


And then we're gonna move it to Windows, but okay, that's fine. But if you know that that is a possibility, protect your application with very solid aside. So I build this facade, your application only tosses for sale said. It's only one that knows about obituaries by doing. I'm also to protect yourself, and you can move from one point. 


There are ways to do it, but you have to understand without the critical. I've had that situation and I teach computer science, classes, partner, and I imply that to students as you might write in a window or uncask. But you know, I, I great online. So don't don't be doing the social need drive thing, don't you doctors? 


Usually and and then you don't, you don't, you don't have to know. Okay, Well something that's actually mentioned about homework. If you came up, 21, I mean, you use only one team on the, you know, in the subject line and of the file, that's another which one and clearly put your names five. 


And then I know that the thing but just don't send me true. Too puppies. It's still different pins and is too important. That just came in mind. If we it is, when you talk about having a team of in your two people to work on this time, it is a day because one person that's it for the semester isn't more of like an ad hoc basis of you guys. 


So, I only get involved in, if I get a sense that the people are unable and one person is going on the world. Then I start the passenger because I would think you know, there's not a good thing you want that. So most situations have been people just tear up and they, they work together for the whole semester. 


Let's find this pain and occasionally something. Because scheduling that I don't I don't understand. 


How you just pick up a four digits being like it for the band? And you just visit the and he did the conflict with some of the students. I tell you administration that means they should difficult but be easier than using last name first names this. And then some penises a picture of different numbers so it can repeat. 


I don't care what it should feel. Would like to thank the HL methodology in software ones. Spend a lot of time on it for two reasons. This morning is that for much of the industry. When they say hi, child means you're free to be a habit. They don't really do a job. 


They pretend to do. It can also again, you are free to be a guess code. Don't worry about designing, don't worry about the requirements. I mean, so so that's one. One problem, it doesn't all understand what design is and then ask them other requirements are and they just only sing, you know, it's coding of has limited or yeah. 


So we do coverage like that students are using how whether they use our child or not. I will not accept to work with anything that is not building since impermental, because you have to learn from your atoms. All right? I had I was on the product of product of kind of was in final stages over almost marketing and things like that. 


And core to the product was a dual important memory. There was no driver to the found for that dual ported memory. They assume that they'll find it one day. Well, you know, you have to plan things problem. So anyway, Okay. So today, we're not going to take it services to me, okay? 


So I wanted to relax and basically come over two things. One is give you a sense of what we have about the computer science field is done in terms of formal, verification of programs. Why? Because we're going to do a differently. 


But we are building on. So we need to understand that the same is that I like it to appreciate how complicated things can be. So when we make them more elegant easier to understand, they say oh yeah this is elements and compared to that I don't want to do. 


Okay, that's part of my So what kind of to be able to work in this class? You need to have some basic knowledge of credit, not very sure. You need to be able to know. And okay. 


01. 01, 0 and 0 is 0 and 1 is 0. 


One and one, it's one. Y and zero is zero. Then if it's a standard thing on the same voice, okay? You have a problem using table. You need to understand what the implications implies B. So, you know, if this is, this is true and true that on expression and this is false care. 


What this is is called expressionist because if I play with the promises false, doesn't matter single school. So we have to understand what you can only do things. This is true. This minus 2 and this is called of the force. There are different. But like I said, it's basic, it's not something, you know, terribly sophisticated lead to understand, qualifications. 


So when you say for all x sides, that x is negative, then three whatever. This x is volunteer this condition restricts, a range of values of x. And then there's some credit here, whatever. Some problem of an exciting and abusive but those are really good, fundamental things. So if I if I use here 3x and and saying, okay you want to sleep, you need to be able to understand it. 


Hey, it's not pacifier here. Okay. Is he spending this formal as a free variable so that means that, you know, probably there's something here just for old kids, right? So, this scope is important. This x exists only in this area. And if I have another x outside this x outside is not the same thing with the x inside, we're going to watch some going to make some mistakes and learn through it. 


But a very basic breakthrough, lunch and party vacation even only and you didn't work on anything because focusing is very based on based on life 


Like I said, you know, we learned from mistakes like this is, I mean, it would be very helpful to understand. I'm not saying that, Well, we need to schedule. The kitchen is something new and specific in many different contents. So, 


Area. 


Why you write something like, anal texts? Already called x plus 3. What does it mean? When I think that's what class means, what's for evil means. So I'll let you see that precise definition for those things. We have no ideology problem. You maybe call an equal means double now. 


Double themselves like you do x plus. Plus but you know communities. So in the program languages people understood very early that we need to have formal specification of what the language does and techniques will build to do that. In the basically, there are kind of sleeping three types of techniques notification. 


Operational. 


And actually remember, 


For different strategies that would use for complete mathematical description of what the program language does. So in them, in the innovational, semantics program was used as a function. So the meaning of the program, so you don't know is 20 lines of code. This meaning of this program is a function f, when the function left us, it takes an input. 


It now to be done. And then the whole problem, that all technologies that. How do you discard this function of? And so basically, thank each statement. And each statement is now model as a function, and you have two statements and you compose those two functions, they have three statements proposal functions. 


That's an etc. And that's a way to describe how this meaning of the program is captured computer. And then you can have a precise definition In the operational. Synagic what you do. Don't you basically say, look this program. Incidentally in programming and surrounding my machine but the machine is not the real version. 


It's a very hard abstraction. So if you describe every statement, you basically have this machine that you describe what it is and describe the state operation can happen. And then the map each statement to an operation. You know, basically kind of translate the statement into a large part description of the impact and so whenever the woman has like one you have trolley. 


I mean the way you explain that, we show what happens in our strategy, so you show that the particular memory which is allocated x changes from what it was. So it's operation. It's really like that is cold translating the current occur. But the thing is that the trumpet individually abstract code, that is easy to understand. 


These new to man, Well, some of these operations, semantics were very sophisticated. Like, for instance, the machine underlying machine was a tree to the time program is represented the big tree. The memories represent as a tree and the program counter is some something that floats in the tree and then depending on where the program is out there is now modified the tree. 


So, you know, event somewhere, like I said, can be very sophisticated, very, very complex but that whole idea is to have such dandelion machine to be so well, designed be fine, it's not ideal machine. It's an imaginary machine. It's so well defined that if you ask a question about the program, you can the machine and you don't have that Axiomatic is based on large. 


So we describe basically describe the semantics meaning and that's what we to use of Eli. Roger, We describe the meaning of an operation in terms of logical. So there's a good picture. You want to say is that if you understand the feel and you execute this payment, you can end up your status as a public Q. 


And so now you can have two statements to compose as one of they have to replace electric and expressions, just to see what happens, you know, impress up there meaning so you can see that we have a statistical program. The whole meaning of it is equal to expressions. One detached angle doesn't want to cut as a hole because that's So this is a kind of thing that you know in a good classroom and we're going and it's it's beautiful really elegant. 


It's important part of what? No specification. However, and you also use the software engineering. So this is specification of programming languages, which generate viewers some mountain things. Former specifications. Because again, it's very important to understand. People realize this was critical in another languages, actually have very well before. I semantics Some of them are not. 


Just injuries description was statement and that can be problematic. Another here was specification playing around making something. 


And the day specifications and involvement in many different levels. If you're building a system, generally, we talk about requirements. 


And you find the clear that we find engineering. So that basically specifies what the whole system was a whole is going to he dependent on how it's going to be built. I mean and all of like a point. You know, something you guys when it comes to the friends, they formulas get their by themselves abuse because an independent technology is going to realize but I'm dependent. 


Okay. What fundamentals? So the design is different but so these are requirements generally focused in the level of them system as a whole. What does it cost to make? Can you can wake your hand and use English? You can, there's very precise models in some sense. It's essentially so much that changes, or you can do a combination of the two of some, some stuff is called formalism. 


So, now, this information, we're using really components. 


So, nothing inside, that's a software architecture, In some countries because I'm trying to consist of two kinds of things. Connected in the compliance, the computation and finance systems. Okay? Now, I want things component, and send it to China to be manufactured coded, and he told me by morning. So I think start like this. 


How does it person receiving this component? Know what to do. If you just go to the name short and novel of short, right? It's not besides and you're gonna get code. That doesn't do what you see, you should so you know, whenever so he wanted to be able to be stupid award, you have to have very precise specifications and that's where another place where he has this specifications. 


And specification of which means that they're right in level to program lang, save the component is a plus. Give me the signature, you know, a message. If you don't have minutes to find all the times and then explain to me what these methods does. That's what is component specifications. 


Even all of that in order for somebody to return to you and system that actually works the way you expect, If you just give you the signature, get the method to arguments and the types you're going to get something that you can actually invoke. You can use it but may not be doing what you're saying is going. 


And if it's a body line program, you can figure out that they they got to draw, but it's a 10,000 line program which is more API interface. Forget it, you're going to spend days and days and basically the debugging and figure it out. And if this is a concurrent system testing doesn't work by friends. 


That's why we're doing this course. So it's testing does not work people have two components, so I'm a component that five states in between another component, first thing between eBay, when I put them together, I got 25 seconds, 50 cents, a hundred states and this has a higher space, you can see how it blows up, and I think on a system that I, so this is a trigger system. 


I should be able to completely analyze it by intent and then I took a piece of envelope and I sent it right in how many variables are and he's variable as a range, forget about the fact that individuals are in very large range, but let's say reasonable ranges, but to cut 20 variables, you got 2020 if they're buying them. 


You know, His advice and H to the body is that words? Because you do to the point, how do you gonna make sure that that's all the places? There's no way that's why we want former fingers, it's always going to rely on when we can come forwards. So anyway, so requirement can do something that requirements with performance and also using in that kind of a program level. 


So, he finds you basically to sort that numbers, you know, I should be what that I I'm doing filter negative numbers. I mean you know certain numbers and collaborative and solid things, it depends on what you really. So and and the program level, we also want to talk about verification. 


You want to prove the program, correct? Because the program is short. Now for most programs fall notification over here. But if you're going to write a proposal communication protocol, the better explain, clearly what the properties of protocol have to be and you know, improved that the product will actually satisfy the problem that you want to. 


Okay, my beautiful looked at mobile IP, which is a parable for supporting mobile nodes, that move around the internet. 


Mustn't. Even prove because it prevents no good ideas. It's still works. It's the use. It does not, we proved everything. There was all the packets for the destination under this long list of assumptions. Well, but we never understood the limitations of the algorithms. We understood what effectiveness would take place in the networking people. 


Didn't specify formally equipment. 


Okay, So one computer science type of game. 


Drug systems. Something engineering that was a term like this edition was in 76. So we're just 70 is most of the people are starting to I was interviewing and because was a new field positively over the country, places hidden number. So put into games. So so anyway, people of your science, stopped it great thinkers invest in effort. 


This is a political products which means small algorithms want to. And so for identification, 


Was an important aspect of what you're studying. I'm disadvantage of another one. But from what's the link in the element was the question of how do I prove that the program is quite and that was you know, and this is a question that we didn't have an answer. So people start investigating trying to understand, you know, what it takes? 


I mean, and this way, 


And it's a specification and then you take the code and you compare it against precipitation and you show that the code meets us specification that needed. A quote is correct. And that, it's those concepts. We're just evolving in a people. Didn't sing them. So, the usually programs are separation. 


What does mean a program is equation? Basically in the correct answer code and there's a program content it's a memory there was a state of the data but if the program counter is actually this instruction, you can one that's it CSR program. I see my specific. I mean there is concurrency since the profile but is really brought underneath and that's one of the big famous in computer science. 


We did not actually think of firmness between that and basically said superior language or waste conc, that's kind of observed, but that's what it mean. Ada was one of the first languages that really had from France and filmed into the synagogues. We have tasks and this management has three more variable Java is being none of a good CNC plus. 


Plus again, the compass is brought external. Not really the problem and natural. But anyway, so listening and actually, very special guard. One of this and so programs are residentially one instruction and the next, of course, if and jump back and it's still one instruction, man. Hit it down. So productive. 


What was specialist. Okay, So people started asking okay, how about proof at this program? That's what I wanted. And the very first person to do, that was Floyd 


So he was interested in that time, the way we discard code. These approaches what I missing is that. So please. So, you have start here and here. 


Or something problem. And then the company. 


Obviously, So Floyd, here's the first genius. I mean he was working as an item operator for them. I don't know what is situations college degree was or but within style. And this publishing has a night time over later in the bank and Tom Jones in the country. So he moved from that. 


I think the standard because it professor. So I mean kind of gives you a sense of the kind of person. So, he basically asked the question. How do we prove this kind of program that can float shots in arbitrary, flowcharts 100. And first thing, he realized that two concepts that we have missing, you know, there's something called partial brightness. 


Another one. 


And total financing is partial. 


So basically, when he said, I can pull the response right under something terminates, but to really be correct. People don't need anything else. I also need to prove anything. So he came off as a concept of breaking roots. Pretty compromised in different places and the socialist bubbles predicates. 


And then proving that if you come from here and you go through here in which now the credit at homes and two builders, you know, all this equation. Piece of code that being correct. They want to put them all together so comparable, okay? But and difficult it was a mess in English. 


Arbitrary loops. Now, whether arbitrary use came from from go to and remember that it was going to and the things in the famous paper vocals considered perspective, the major controversy you know should be eliminated go to the programming languages. I'm gonna go to San Jacinto here. I mean, So what's interesting is that came out about Kadimia, people looked at worked at the programs and if I don't have vocals, it's easier to understand. 


And then you see screen, no way. We need a voters. Can't get efficiency in front of the logic. We want to know what and then again from academia, something carriers came out with the proof that any program that has go to can be replaced by problems. All builders. So show that there's a new USity there that, you know, you don't need to go to imprisonment now, there's going to be for practice, whatever. 


But eventually that's got it was structured programming languages and broad structure by this and what we have now it's called and basic, it's practical problems. But important thing is that people of the business here again, I'm not giving them things to stands out of the challenges of these old history, powerful community smartest people in the world of your science, went through this process and now we know where wiser because of it. 


But important thing was introduced predicates and called the bubbles, okay? To be able to see the piece of code, linear piece of code does what it's supposed to be uses political. I mean these bubbles to cut the loops so we can, we can see only pieces of sequential curve but that was his technique when I'm really interested in intending itself. 


What you're interested is that introduce the use of predicates to think about programs and we introduced to causes partial and total correctness. That's a key. That's a completely particular evolution. That is still relevant today. No later on before. 


Started programs. They don't have books and don't have advertisers. So basically it looked at structure colors. 


And so that means that we have sequence painful body, we can have 


Do not. 


To get the logos to move. And we have, 


And then all the impacts. I'm not good. And again idea, was this if you have programs it has a satisfying properties. Then verifying them is easier. And all if I can verify these here, maybe this problem programs are actually more comprehensible people about people, they don't buy something certification. 


If I can actually manage them get so much controller for them, you know, visit it's easier for other people to think and that was kind of the whole thing. And what happened, everything. A lot of what to do today. This class is basically has its foundation here and what he introduced a key concept that we introduce what's called the whole tribute. 


This concept is fundamental products but basically says, is that famous feminists. The way to reason about it is to show properties of the, for, if I started mistake a satisfied, speed can understand exceptions. You can buy, then I'm going to end up in a states of responding so it was really 


This equation. So basically gives us a way to characterize. What a statement that what is the amount is still a change from. So basically, so the different between this mistakes has to do with the fact that now I have to make a change by the standards. So in this state, then diagonally was zero. 


And basically this thing with S they draw memories one wanted to do like doing the memory and then the next time it takes one and jumps back to zero on the next thing, which is 075 whatever. Okay. But just having properties of statements statement changes. Remember you exp and tables and by introducing this then he was able then to describe his programs the same exact same as the programs can to prove properties of this product. 


So, for instance, if you want to to prove the composition of two statements so PSQ but then this is 


Let's make this one, this one and then this one is two. 


Is done. So I have two segments, independent and those are the kind of problems. I can feel about it. These are going to change the memory. This one is kind of changing my history. If I put them together what needs to put them together as one followed but has two right? 


For example, that's okay. He turns out that few impacts are then I can think with that's going to. So see how the composition because now this takes us more. This is true, which implies are takes us to die. So you can see how the high degree is to statements. 


I don't have to worry about them intermediate state anymore. I can improve from each property of this statement. A problem has 10 years rules for dealing with with the Ethernet and as it was the beginning with the Wireless as well. So, 


You can see that he was able to deal with programs. Yes. So purple for us one. Is it implied? That means you have to be different states because of the art. Actually there's one oxygen which says if you get to this time escape the meaning of statement scale is doesn't change memory, which means he skipped it, and we're going to use something, okay? 


So we're going to understand that it is to give the stress of the approach. So, the approach is basically using predicates to describe what statements do by showing relationship between the memory before and the memory of, and that's the principle. And with this, like I said, we can do the whole. 


Is that improving programs? And you also need to do is stimulation. So when you have loops, you're going to have to that rules like this for being with others and key to the root beans are lost in the notion about this value. 


And we're going to borrow that and use it again and again ever again very helpful products. Exactly. And properties that don't change. So, the looping value is, basically the property that it's true and it started look and it's true, every time you finish them. And it's all you can prove about loops embarrassing to complementing else. 


So then you do a separate through of termination, you show that the blue country will eventually terminate because you terminate and then you take the invariant and the termination condition put them together, say up. This is what the look accomplishes at the end. And the loop is really for their valued is really reflecting you are thinking about what that algorithm. 


It's important in. The look, it's a way capture after you don't think so. For instance, if you're if you are creating up on a way and you move from left to, right like this 0 0, 0 % at the end this year, this is you are thinking just appropriate informal thinking, right? 


I can explain that to you, okay? First grade, okay? But not thinking what you're doing really. We're paying is basically says there's a variable here for you. There's a pointer here and everything you back to. The quantity is zero everything in front of the point. That's all the battery. 


It's very feeling captured. What we intended to to defend them is very fun spoken. So like I said, we've been able to build on this but everything that prophecy is so far. You know, just keep on your programs and the very important observation that come back to it later on. 


This proves are based on the text of the program. 


So, when in your text, you say, thanks for calling equal zero. You can prove that you're not going to be a state or Texas deco, but you see this is effect on the problem. It's not some bookkeeping fancy. Looking at students around me just purely, replace them programming and that's better. 


This help looking program improved. Probably the that's going to come back. Partic proverbial aspect Now Like at this minute. Okay, So now that other people that have contributed on this, So there's a strong segment of foundation that has been used and if you want to prove that system by the C system simple larger program, the large parts of the program are sequential, and you're going to use this thingies. 


And most likely even is machines in your system, okay? But we are really interested. Go beyond super products. We're interesting for Christ because that's all. So the question is, what happens in the comparison? 


I'm promoting languages. How do we model profits about that? Well, one of the very first piece of work is 


Degrees is the common figuring computer science, Oregon Grace, first came out with diabetic. Let's see. Introduce some abstract notation for concurrency, and that I see whole two properties of program treatment ideas. So basically there's some together sequential program because every single and I'm almost there to the product, so I should say that sequence. 


Generally is beloved by some column. The dual is generated. 


Will be present that conditions on each branch and then it's analysis other. It's not the case most. So, if 


So that's the first I'd like to computer scientist. I mean, we want to go into a published paper, that's what you're going to, okay? So these basic effects, the loop and the gods here and your conditions. What we should take this particular branch, and when none of the conditions are true, we have to get up. 


And that's a, and here again. In fact, the case then choose what is the more than one is to against? So that's so even this kind of limitation culture, basically, they extended it in the same round, we have something like, oh comparison, first option. So they statement one, seven two special for now, you can see how the different semantics here. 


For instance, the case you can think many of the cases such as choose one and answer because for this, you know, the same thing. But you repeat it. And in no case in the past here you branch friend Another different branches. Okay. But these are simple. Different substance from state already, done, okay? 


So, the problem is other improved, properties of this whole group, and the situation is appealing, you can prove. So, you take, let's say a sword, and you can move to prove that some properties of a soil P1, this one. 


But what this is doing is proving that as one is having this property and isolation. Okay, so let's say the improving this one. A very important property is that x never changes and that's critical to this problem four. But here's this one, the place is x with this present proof anything that you close about. 


As one is no longer true because it was only looked at that code. And in that code, x never change. Have you got another change? And you could say that. Why, and you go to see because they both have been assigned but you actually can change. You cannot prove that y is equal to because you know things that so they cannot put their concept of money. 


Interf. So you do this proceeds and this so you know, so you have many segments here. So there are many predicates between the standards and then you have to prove separately that none of the other statements can be stored. Your proof. That's what's going on interference. The other statements cannot destroy properties. 


That are important in my group. 


I'm exhausted just telling you about. Yeah, so so I guess and so so proving if you can show that they don't modify as something to the other statements, then you can prove them an isolation and that's okay. But is is that I start a dividend suggest that if you do have one that modifies you can't prove anything no more just about the issues, be modified, the proper shared variables or not. 


There's not any stations that you modify the share variables. So for instance, I may be by in my proof on the fact that x is greater than 0, I don't care. What value you? I've modified X but you're moving it almost half a dollar but you're keeping in about zero. 


We are not interfering with my proof because how many won the fact that they response did not or the exact number, but X had. So that's what you have to do. And of course, we have no combinatorial situation because you have to take every, you know, every combination of statements and all the predicates for every statement and make sure that they done disappeared. 


So they so that a lot of work here and also if as two here it's a call stronger. Now you've got more work. What? Company, you know, Now assume that it's our sequential then what you do in the end basically say behind 


So if you prove property of each statement, then you can combine the all this assumptions and all the results. And now you can say that this is why the whole thing does the message. However is that I will not want to do this. Concludes the painful, the complicated message, and I would hate to spend my time. 


So we need other ideas that are clever. So, one of the ideas that came about Temple Logic. 


So, you know this video here was known interference. 


Temple Energy. There's a very different view of the of the program. So basically it's just what is the program? He starts? This animation state can be more than one is, but that's a one, interesting state, certain amnesia state. That modifies a slip. You get into news and there's no music and this concurrency in the next state, maybe this or maybe that. 


So now your branch is concurrency again, your branching. So why would think of it as basically? We have a program. 


People is set of behaviors. 


And this is kind of the whole possible. These things. 


So you start in one initial state music next, if you connect and there's a concurrency. So from YouTube, get from this event there. And then from this, you branch here, so behavior. It's a line like this to this tree in the kitchen tree from the from little state to be. 


So if you take all this minds combine so you have anything like it you've been in tree has number of paths so you can single banking on the pass. So basically, you got now, you think about the program has institutions. And I notice these guys here are looking even comparison the text here. 


The secret question, programming with who's called knowledge, look at the text here, not only have to think about execution sequences which are the infinite, there's not quite looking at a text. That's a really a very different way of thinking. So what you basically introduces something about state stay formed us. 


And the staple should be something like this. Same. 


What is sigma? Singai is one of this infinite lies. So they're treated to the execution, what is Jay? Jay, he says position his life. So now you can see things in very different way of thinking about it. You can say things like in in the third position on sigma, this property is true. 


So, you see how we were thinking of? Where in the execution we are on a particular institution and we talk about that properties are true that. Now in these local little bits counted, the company can increases but it goes out that once introduces notation then they have some richness that can live. 


So for instance, you have a point of next, if you look like this, 


So what business says in the next state he is not neutral, go straight to his hair. Sweet. And this is for basically saying that state fourth is equivalent of a property piece. So basically, this is in the next state. After executing this statement, you're going to be in this mistake and you can then enter the something. 


So basically, then semantic satisfied me as a very precise pain and then you can introduce things like henceforth. 


So sigma, okay, in the property of that. And force people. These properties said that in this area today's state from that on things always like it, true forever till they infinity on those. On that death. You can also do something from the eventually. 


Which basically said, if sigma is this in the eventually a state in the future that would types like you don't know how far but in the future there would be something inside and sports and eventually, I'm very, very critical now aware of thinking. But here's a pleasure. We are going to use capital logic. 


We are going to rely on the bi, but we will think directly from the text. We will never think of this execution and that breaks through that, we get through the model of using it, a specialized version of temporal logic. That simplifies things in such a way that you can actually. 


Look at the look at the text based on the text. Not about trying to imagine a characterizing describe long synthesis into of ex. And that's, that's a so we can learn how to reason about current programs without having to deal with such complexity like here. And without having to be kind of falling into the sequential mode of thinking. 


Because this is within a particular, second floor way consequences of profitable to complete complexity and regardless, in a way that if you look at the code, we can actually put properties like transports, basically, you know forever from this point on forever. It's probably true. We're going to have a notation for that to be much simpler. 


And see. You can't the passion to prove that to come really true. God kind of thinking through all the possible exe. We're going to be able to prove that we just looking to cook. And that's, that's a power of what the method I'm gonna do. So the model that you can be using is computing, 


Because this time, 


Please, you didn't bother me. 


So what the idea behind me. Very simple location, a prophylactic associated with their notation and notation that is justified by the need express and move away. Find and then the ultimate design. So the design release takes from how to approach this. So, 


When they basically have been, they said sequential programming is getting in the way of us thinking about my kind. And it's I was working on a model of CSP and this model gets and the very important model and we're doing some mathematics. And then we're having no trouble with the comparison. 


Part of we're in trouble. Is a secretion communication. Was getting very complicated, very messy because of sequences. Not because the concurrency finish. And he says and then I discovered their work before even was published. And then maybe I spelled this is a approaching from a punitical kind of perspective and you'll see next time, how the locations really purely without the other? 


If you answer question problems In this language, you have to tell them and it's a mess to cook them. You have to introduce a variable, which is like a program counter and then he has been here, method variable. Every time you need to stand up to control which is the next thing with it. 


So writing sequential programs it is notation is going to be messing and pleasant and not something we're going to do. We're going to write concurren. Yes, I want to make sure I understand what you mean by so good for me. Is this slate? I'm thinking about a program that I could email different threads and creating child processes that do things that kind of your foundation is upon in computer science which are about different. 


It's physical so circularly they have everything Clark takes an old surface, okay? So that part of it, Currently the Dodge part level. So, yes, if we have two slides running on two separate cities is not the corner. We are running in parallel, but I don't know how to deal with. 


So we have structured and basically, say, without any receiving, a logical problem. We, so that's our comprises. It's logical. So lots of requirements are basically says you can have any threats and each one executive statement. That's what is interesting, is the same and you can palace that tricks in there. 


But yeah, okay. So basically you have entered we are using internet. Easy to simulate the execution of the, and it's a reasonable thing because, you know, if you have one mastery to use this, exactly, the compression system does scapes with different tasks to different types and we have no control. 


So what noise products? The basically I'm saying this program is that I deliver this results. No matter what operating system are you gonna use? What kind of scheduling process I'm gonna use subject. So that's what so basically when we think of currencies the interesting of statements, I'm separate things and they are living in happening way and we're going to college. 


And that makes it difficult impossible to test. And that what makes it difficult. Because there's something ways this statement and helping here or there. Remember. And then they affect my difference in hormone. So that's how you need to be able to manage that. Compression doesn't managing the, you know, we can as well, but I don't know. 


I mean, generally place you can On thinking of things happening in artificial orders. And so the overall execution is essentially for us but we capture that many possible secret. This is manipulating so that's what we're doing. So this is an, the thing is that when it goes through the model to imagine, not have to, actually think of this many questions, We think about the code, We drop off those directed from the text. 


So there so they build this model as a very simple notation. I mean you're going to have trouble with the rotation because it's so different. That is really trivial if you never program before, you think that is a piece of, but because you have such biases problem, biases, you're going to run to work and difficulties, okay? 


But you know, you'll master who what exercises in your and I assure you that notation is true means much simpler than any language that you have against that is different than nothing. So minimum notation attached to equal to true project which is based on temporal logic. When the properties are proven connected from the text, you're going to have to think about execution systems. 


You literally, when you're saying this is a property, you go and look at the code and you can check the disparity. See all the way from from the top. And then they showed that with this notation this program, the can come for the they put every important concurrency harborism and they showed how we can express and reasonable and even derived using this location in. 


So they will never be some of these other videos. Basically, going to take a problem and see the mention protection, right? The former specification for it and then we're going to define the specification until the point will be difficult, excited post that from France that worked on a wormhole router and he basically wrote a specification for the World War router. 


Specification and adopted me about a page was three or four pages of definitions in front of it. And then spent six months to actually improve to recording the sense of a finding and refining, it the point where he actually had to develop heurans and to the point of which the code fell out in the code, is on the some exercises, but short resp. 


And they put things that are complicated like algorithms to the algorithms. Protocols. They should begin by make sure that your model was machines and they took the blue base systems. They took very distressed bits, you know, certainly what they took certainly. And then they went down at the register. 


Now, you know, I think that is the next thing about they call the base and the children rotation. They can model everything and they can reason about everything because they can model it. So we're going to rely on on there and thinking and I'm going to be so interesting. 


So, I'm interesting properties addition. So for is no, there's nothing special. So say Colin does not look at this. The nice thing is not going to exist. Termination. Basically they say no termination do antelope racism determinate that's what you have to prove. No, there's a lot of programs that never can make and they shouldn't So, termination is not a session. 


It's a concept that we need to move from one face to another. So if you do need them to write definition, then when I did that the testimony and they go after the point where basically our problems are going to have to infinity whatever they need, stupid machine can tell that my program is not doing anything. 


I can stop So logically. I don't care about that home programs in this. 


So we may be able to come up with our answering three steps, but the program is run forever. We don't care. So you very different way different way of thinking. So we're gonna focus on the representative state. It has a variables, It was that comfortable? We're gonna present comparency is a set of statements, not a sequence. 


It makes sense. If it's a gradual, you have to have a sickness, but it is not sequential statement. And then interesting and interesting, don't come together and they work the new program. Now if one synchron there are mechanisms and tax across and there are synchronous machines and that we need to be able to simulate those I guess and I use his model to build a different model for mobile meaning. 


So I use that to describe, basically what my system currency, because this is the beginning. You can have a series of machines and it's agency that actually and model the same thing. Exactly. The same, whether you know, the machines from one machine, you have operating system at the sketching them multiple of systems, but we proved that under the divorce scenario computerized. 


And that's so impossible is very conservative and the worst conditions, including another syllable, and we'll talk about that. An operating system that knows you. By name in any time, you run the program price, commissioner that program that system will improve the premise of. I mean, so that's it's a very different way of thinking than and we are, but everything's gonna get them up all the problems. 


It's all interleaving of statements execution and definitely so far improving and concurrent system and it should never stop but it does stop. Then I prove that it's incorrect, okay? 


You're not quite saying either. I think we can sing. Whether it's also, if I if I proved that funny because she's not done me and you do the proof. Another said, and the other notes, there's a national termination different, it's basically called the fixed point. It's a place where the normal. 


Pro those kind of. So thank you very much, Pleasure to meet you. We'll get to know each other very quickly and the please send me some pictures remaining the name. And the next week we're going to study the recent rotation because first assignment and we get this is all different. 


But warm ups Merry Christmas. So no homework This week except sending me the picture and the name. Oh and the format of the subject similar to what we mentioned. And then, on the format of the subject is that the password 


So, the reason why these are the subject here is the probability. 


Called Uber, That program is incorrect. 


Basically. 


Have footage of everything, isn't that? 


You don't hear from another picture. 


All right, so it doesn't stand up that property here. That's so can you get into this kind of important? 


For your talking about horror logic, and the sequence. So this way, he is one two and one is two about you but they don't need to prove that few implies are I need to proceed things? Have gone this time and does this this thing has that and this is relationship between the time. 


Oh also. So there's three obligations per. And I think when you are talking about a job parts of the agency that you use, maybe hacking. Oh, thank you. Yeah, take you. Yeah. Why not just calling all of us? All you. I say it's sometimes. Sometimes people say that we have hydro maybe just packing it up. 


Oh, nice. Yeah, I think. All right, see you. 


What is the exit to go to the Notre Dame Street? For example, if you go to the right and then okay, 


Maybe fall down or element. Conducting professor. Oh, so that's 


To be a little bit of a