00:46
Small pictures. That shows your

00:56
So what you've done? That doesn't.

01:06
Safety. Okay. Just informally kind of see, you know, I'm outside reads it and makes sense. So what's going on Then there's an abdominal specification. This is.

01:35
Remember our system status, right? So same way that you declare variables in the, you know, problems the same way that abstract because they represent things which are not variables in the system then represents. So, for instance, the let's say that you want to notice speed of the vehicle, obviously you're going to have to go to the campus.

02:11
The campus is going to talk to this speed, whatever the sensor, and then it's going to return back in a value to you. And that value comes into that driver and that driver. So it's really message passing, you know, multiple layers of. But we present abst as we successful twice the speed.

02:38
So terrible. Anytime are very high elimination.

02:56
One way. And why they use that very And there is a kind of very that single meters things that we had that we don't control. So they are outside of our control.

03:30
Continue.

03:35
Application of something, we can't control the speed of the car. So some of you for instance, talked about, you know, eventually the car is gonna stop. No, if the car is actually air lifted and then broke into ravine. Yes, the battery is gonna stop but it's not what you mean, okay?

04:02
You don't have any control over the car if the wheel satis engaged from the brake system, completed the cables and the car, you can't stop the car So you can't. Write the specific reason. We will start the car Polygon, right? Is I can apply this break, whether they're supply or not certification.

04:23
This would be like parking brake different than the cable break because okay, so if your brakes are bad, let them lines on the horn. You can still pull the immersion upgrade on, but this is a emergency brake. This is what we have described yet. They've noticed right? Yeah, this this thing that you yeah, talk about where replacing it was about.

04:48
That's already. So it went to the brains on the pedal. Yes. Okay. It's actually a disc brake. It goes. So, there's a disc and the one present pedal. This same practice with this, can slow down the this break, it's cable for keywords and the they use drum. I mean, of course, different design, but that's a typical thing.

05:17
There's the drums. So basically, apply the pressure to the front And to start the cover have two separate settings. Also, you know, when you are informed, doesn't necessarily mean that your, I mean regenerative process. You know, it says here is we stopped. You can move, but that's not true.

05:35
That's why, you know, in San Francisco. They tell you you product, if you're going downhill in part was a wheel store that the sidewalk and the food of emergency brake, that's an equivalent legal requirement. Oh, it is like a locking that number here? Yeah, so yeah. So you have to describe what, you know here, what you're assuming but we are really only controlling instead of a controlling this brake by hand, which we could, we could control it by hand.

06:09
So if I'm up going up here, when a man was manual car, you know, I'm working with my gas but it's also working with my emergency brake up and down softly to be able to work with all that. I mean, I don't know how many of you have family.

06:29
Thanks for your loss, man. You play with that brain, you know, my wife's super, I mean, press a button and then it goes and walk out the hill in the coconut So. But anyway, so and that's usually you don't have a customer. Normally you have a customer in the customer, will tell you what they want and then you instill.

06:57
Those same, you know, it goes for normal requirements. In any process, we are really learning how to specify see it? Not really. So any reasonable specifications come up with this result? I know, but you have to be able to actually capturing problem. So it's important to remember that things that you control since that you sense, when information that you're getting from it on the car and then essentially control and don't listen discussing so abstract state is another section and then it's a specification.

07:37
And by the way, here, you can also make it to some definitions. So basically, if I don't have this B, can be APIC. Say the under of pain is defined as v. Equal a. And now you've got the definition 1400A so you can use it. That makes a specifications clean.

08:11
Okay. Now What's available to us, massage to specify. So, some of you have used

08:22
Told you this represents short you can never use sensuousness. You can only use insurance and including the program code because ensure says, find a statement, which is guaranteed to make this, they have no statements. You don't know if that's gonna be not even one statement on five statements. So, since you don't have any control of that you can never decision.

08:54
No means to generally make sense by the problem with needs to is that it says eventually so you can see. I press some of, you know, you know, I present break and eventually the car stops like I said that's that's not correct because we don't control the car. Don't put putting that aside.

09:15
What that statement when you write it, like that magnetically. It says that they maybe today we tomorrow maybe 100 years from now. The car is not stop. So he's used this. He's doing doesn't have strength Now. Something that has more strings is until which is really an theme of the Q leads to queue.

09:53
And and this is not the logical end. You have to do two things. And he unless so property, still stays true up to the point where eventually. So basically says, these are three states, two or space, whatever Facebook forever. Or if it does, become untrue established you because standard alerts.

10:24
But these come to the right key that by the establish key, which I'm going to, I'm going to tell you, the eventually we're going to get into, so this is stronger. But again there's a leads to internet which might take a long time and some situations with climate issues, there's not a problem but so you're going to see developer problems.

10:51
You know, you're going to press a button and the eventually then I was going to stop at that floor. Well, and you don't want the button to turn off in the meantime. So when I have to and I killed, make sense this. Okay, but I'm not here. One thing is that maybe right Now if you really seeing that, somebody that doesn't kind of just stand up.

11:20
Engineering, it doesn't know anything about performance was doing this on the way. They would describe this problem but basically they put a tape and they would say, okay here's a speed of the car. And here is the break application. If the speed is high, he breaks 33% in the speed is low.

11:43
You may have 80% if you stop to break, that's the way they'll do it. Most controls you guys. And so, yes, it takes some time from the timeline of making decisions by the time he's so short that for us, we can really and we can basically say if the system is in state P, implies the break it is.

12:28
See, point of the break shows up here because that's only one thing we control. So basically, you know, so for this is, if I want, I want to write them a specify problem. Where, when nighttime comes, I turned on the lights, okay. Then basically, I'll never be able to be sleeping.

12:53
Let's say light and we call it bullying techniques through daylight typically explain it that way. And then we have the

13:18
Part of the lights on the car.

13:23
So, it's a business there. I think the outside light,

13:37
Opinion. Bob.

13:48
Might comes up. I'm just outside, like

13:57
And What about this? The ahead.

14:10
Lay.

14:15
Okay, it's

14:24
So then the specification would be an invalid and satellite outside and flies and live through influice.

14:42
Now what this might be a little bit weak because people this person says, if it's dark outside, sorry outside, but again, if you don't outside the lights of. Yeah, only. Yeah. They like that's important. Okay. Like okay.

15:10
Okay, so, so basically, this was kind of, if it's dark outside the light to come on, but it doesn't IP that if it's light outside, the lights go off. So if we want you can do like this, you can only start. Now this may be two type of specification because if I'm in a an outside in daylight and has an area which says headlights required, then I I have to to do that but if they and I need to have a different statement.

15:48
Of course, making information that I have imaginable control, so it's not just that, the outside light is also. The button is on automatically manner, things like that. What you do. Val this one. I'm controlling. This is what I what uses to control. Okay. So that's a style for this particular specific, usually taking the what you know, like I said, German engineers would use a table with continuous variables and things like that.

16:19
We're basically specifying the logic easy variance whether we see different employees. What if I'm not only living by the outcome because I mean if I want because I like to turn off because I don't wait trying to get. If I go to the tunnel, the lights going but when I come out on the top of the wall, then I can only, Okay?

16:47
And other situations. I definitely you need money is not that. I mean, if I want to add value without ever, thank you for. So basically, I'll say control and controlling have to be an imagination which is talk about it.

17:15
And then I have to have the information here that if it's if I want on that one. If I find one automatic, then this is this relationship.

17:33
You got the sense of how you have the professional and you need to write in front of each. I mean, if you know, just a short sentence of why, why is this? Why you very now, there are variables that we currently need. We need, you should know coming in to speed.

17:55
We know that we need that because we don't want to apply the brake and harder I speak. We need to know the gear and, you know, and we need to know and you have to make decisions. I mean it's I mean you need a decision. Like I said, I don't care to be there can make another notice.

18:16
And yeah, this thing but I don't care like for instance if you are in neutral and high speed maybe should apply the brain but maybe it's applied in a different way. It is flying the progressive. Okay, first one, is your reasonable. You know? I accept it because you need to buy this specification, the station to describe properly and the specification.

18:44
So we tried using the you think here, but I would say it's more like part of version I would say that's a different word but doesn't it not matter. What what's happening with that? Well, for this as if not in park and you apply the benefit break probably is perfectly.

19:09
Okay, to fly With anyone know that nobody can stop the intersection, which is not the same as part of interest. Yes. So here are or if it's in here like and if it's in any gear, well, let me know. Some people good for yourself, side that if you are, these few are.

19:36
If you are going you're going backwards and your slow, you want to provide some assistance. So you may have a different level of breaking going back. Where there's a forward? I don't know. I mean, you don't choose those things as long as you specify them correctly. I don't so we don't have a criteria to say.

20:00
Yes, you're right. I'm wrong and they were just as long as I listened to, you're not gonna lose any points and just don't make it to complicate just show that you you know how to specify that because if I didn't change the problem when you're making more complicated, if you know how to do it, we're just modify by the importance of observing this again.

20:24
It's so this particular this is beauty and what what it really says is that what I take an action actually is logically, if it's not a media this wouldn't work but since we you know we ignore the timing there's and want to be immediate then any value Like I said in the elevator that is your next assignment season.

20:58
I'm going to so, quite open this in guidance, community modular, right, that I think is, you're gonna need in variance, but, you know, you also gonna need the other settings, it has efficiencies. So, on the piano hue, I'm using sorry. I understand this. Both of them are true, but they have to be previously separately like both of them, You have.

21:24
Well what I say beyond the queue and I say I have proven people what I mean by it is that I have proven feelings to you and as well. I have proven people. It's like it's basically like an infrastructure. The please to kill comma. He unless Q therefore I can until definition but you can use the piano queue in the specification.

22:04
You could use it as certification press and you'll use it when you don't want to be destroyed. I mean, they take a long time for something to happen, okay? But you don't want people to destroy it until that happens. That's why you have done this. So don't don't turn off the light until I get out of the car.

22:28
Okay, so that's unless it's fine.

22:42
And if, I mean, if you elevate, is a complicated substitute from. And if we may need to do two weeks, we were to expect. Let's start this one week and then, and you have two questions on this. So, how to specify event handling? We do was really. You said, if, if you press the button, the result depressing, the button is a change in the state of the button.

23:14
Oh, so we basically instead of state of their of the button, the pattern is pressed on is not pressed. Also the state variable is updated automatically. I mean, basically. Yes, we can think about this, the state. All the was being that we don't control our control from outside. Oh, the button is controlled by the user.

23:40
The driver. The rest are controlled by the car. You know, we're reading from are information. The only thing we can control is whether we're pride any pressure and how much pressure they apply? That's all. And we again we discretize among the pressure to keep our problems simple. You don't want the continuous functions we could for this.

24:03
We don't need just a couple of steps. I love Breakdown and emergency break the truth different system the way in the regular breaking, emergency brake acrylic. So the bottle is controlled emergency control, but you don't see it. Yeah, you know, because we don't, we don't, we don't care. You either mean, I mean some of you have used that information but it's important really necessarily to me.

24:39
Yeah. How a lot of questions about the because there's too control. The that you might just be friends from the bottom all the way here with that. This only one way we have read. I have a button. Yeah, I haven't had any deep like here. You guys press the button in the detours red.

25:06
Once again, the balance is control of the city youth, because we have two. How do we, what do we have to choose to use the system? But we are specifying the behavior of system, not how it is. Designed, I told this is the fact we have two CPUs. Doesn't exact getting them, specifications independent of the solution, the desired because I have really something about the reason we notice the best design, but I'm not confused about that even if why is the is a failure, there are another one.

25:46
It should work. Great. Yeah. But we know that we have basically saying this is what I want too. Then we take this and see, here's how I designed it. So, it's always worse. And that's what the industry comes. Because 4 CPU is running same software. At the same time and they vote.

26:13
Yes, the talk to you is, senator signals from the city to control the bread from the sport. I'm saying that this, look, we are not talking about that. We're talking about the behavior that we expect. Why do we want to break impressive? And when basically, we're saying that the break is going to do different things, depending on where we are, and bringing the state of the system.

26:43
That's what I specify is only behavior. Not how it's implemented. The question, if you get about the regular break, we don't need to. You don't know them, you don't care because that's not another freaking something. Something you only see is a Now if there's, I mean, I can see that we could have very more sophisticated systems that.

27:08
Check everything, they check the the temperature of the surface of the, of the road and change the community. They check the slippage on the wheels and consider all that. Yes, that's a realistic system. But you only trying to learn how to develop spawners notification design. Okay, that's a different course.

27:29
That's engineering in the project and the paper we were given it says, that could be proven or it says, the candy province of manifesto for it. You don't have to prove anything, okay? You don't have to specific and convince yourself that you make sense environment. Yes. The contractor requires a software to be a correct.

28:00
So, the contractor is a company says, you need to verify the system, So the company has to do two things. First has to write a specifications of it. We've hired you to write this specification. Once it's done, somebody doesn't design. And then as a coding and the design, somebody has to verify that the design meets the specification, Then it runs down to coding as to verify again that the code meets the specific.

28:29
So you see, that's us, but I'm not asking you to do those two things. I'm asking you only to write the original. Yeah. So really care about that. I don't I personally don't believe that you need to care about the brakes. Okay. So we just leave it here about the city and the button.

28:50
And I think out, I mean, I would care about the speed in our gear because I want to know if it's part versus stop. I can't tell the difference, something? Okay, about the heart. We put in the invariant I see in a book. There are some examples of invariant that puts a several conditions and the end then together.

29:24
So but if you can separate them into something, variances better. Oh, because if that you value and pews any value and eyes and emotions, B and Q, and R is also in that, Oh, because being invariant is true and you can use true anyone you want. So it's so rather than writing it like this, create a very complicated expression that I cannot parts and maybe makes any mistakes you write it separately, so I can understand it.

30:01
And what's that difference between end and implication between the evidence and immigration? No. I mean the logical statement you put inside the invariant This basically says you need to do two jobs. Job one in chapter. There's nothing to do its logic. Oh, and implication means that if this true the other part is to be true that application set.

30:31
Oh, he's a peace group that implies Q and Q. Must be truly peaceful doesn't matter what curies. That's pure logic. Oh, it's nice to do is computer science or anything, like it. Just watching that matter.

30:48
Was to in control. What are those three values organization? I mean, just you can use a rotation but you know I think some of you have used. I think in who used to deal with dropping? Yeah, something doesn't mean that the value for all manual.

31:16
I mean you can using as a notation is what these tell me what it is. So you want to use just brackets and you explain to the brackets means innovation, that's fine. So, can I write my question on the black ball?

31:32
I mean for this day, I yeah. So you you explanation when this is true means that it's like I'm sorry you use this even though like and use this, no, it's not and I use. So when the first time die is is false. I mean, I used this to space this beans, this couldn't need to happen to greater.

32:10
Can I imagine this? That always happen. Yes, there's nobody ability. They always have to be produced Always know false, then it's always true But this allows you to be false. If this is false, this can be formed. This is false, and if this is true, then this is true.

32:32
It's totally different. Maybe also I cannot just no, that's not it. It's not the same thing education. So that's my question. So, here's the end.

32:56
So any fourth and false forms false and true, these thoughts falls and true it scores through and through its true. Look at enemies. Oh, fly.

33:21
False implies false yes false implies true. Yes, true and price poles. No true price to yes oh yeah.

33:38
All right, let's talk about the elevator problem.

33:48
And then dial here. Take the same. All right, so I'm going to read text and we're going to slow down, okay? So you are also developing former specification of the requirements for the elevator system for C1% of the single cabin and the building was as close. So we have end floors.

34:14
And have one.

34:25
From. And in addition to call buttons on each floor and request buttons inside the cabin, the system has access to the fire alarm. So that means that we have for every floor. We have called buttons, example of it's a whole one.

34:54
And inside, inside the tubing, we have request buttons.

35:10
Okay, In addition to that and system access to the building fire alarm. So, there is someplace.

35:22
And anybody can prove that our allowance is a particle.

35:32
So that's a system that we tried doing this end floors cabin. Their thing is that the floor is at the known north in the cabin head. It's on those to the doors of the hospital.

35:58
Now, your system may have a lot of other things, including, for instance sensors, There's nobody inside the in between the doors. Okay, we're gonna do that kids. I mean, we spend, I mean, you know, sequence of semester in the software engineering class, sometimes, usually elevators, an example, and it's a lot of complexities all the sensors and the dynasty video provide.

36:28
So,

36:33
You are supposed to develop a formal specification and what are you going to learn from this developing this home? Well, first of all, we're going to learn how to develop noticing, is that I'm going to the process of dedication of refined that you start this generally, you stop the specification, she's ready to stop.

36:55
And then gradually concrete. So, the way you're supposed to or paper is being thrown,

37:08
And then the next thing is the abstract statement.

37:19
It is important to use good names, you know like I screwed up there with daylight I mean there's good names that make the specification easy to be easy to understand if you need to use some definitions to simplify things you know that's that's fine as well. Okay, like for this is, I'm not recommended but for suggesting it.

37:41
But, you know, if you want to introduce something called co-located, at Florida F to mean that the, you know, that the cabin is that Florida have and the doors are both open or something like that. You know, you can, you can build definitions in the old, part of the aftermath sex date, and then you give additional definitions.

38:03
If you need, you use the definitions only. If they simplify your your presentation, they make it clear. Yes. And even those addictionary or communication like formal, definitions by these equal to B or B, okay, form of definitions. So you basically have variables and definitions and they've been in the variables of types I could believe before.

38:38
It's bullied and numeration, whatever? Okay. You are very looking in a rate you know that influence is clearly, it's not

38:50
Floor of now do not focus. On causes the interest in change. In this part, we are not interested in constraints between variables and things like that. Now, they're only interested in specifying. The time is a type, is it the valuableian then in this bullet type is an innovation in simulation.

39:19
You don't have any least of these. So, only if you talk about the range of val take, not how it changes, not how it relates to, as a variable passing.

39:37
Then it has then you start writing the specification that there's three specifications.

39:47
And we want to see when you going to ask help yet abstract state down. First, don't worry about the introduction of the cellulitis. For questions, do the abstract statement, get feedback on that, make sure it don't have any major arrows in it. Again, Once you're done with that, only focus on specification won't get help morning.

40:15
This education process was so just what bleeding on me. Don't try to do a lot of things because you know, if you've made a mistake one, just spreads all over the cycling. So in the abstract state is definition, she did, you're finding not If not, if you name could you find a particular condition of combination of variable values?

40:47
That's one user definition. Okay, So instead of writing for all students in the class, the grave is a, I define the function called the whole path. A purposes of paper, And that is for all students that class have created. So that makes it easy. So, I don't have to copy that formula, And again, So don't even simplify the presentation.

41:21
Okay. It does not single constraints between variables. Okay. Do not think about, you know, the doors that you open here because open there and think like that in this session only how we discuss this No specification. One provide a highly abstract and minimum is realized as possible specifications of the requirement.

41:50
The system must mean, such a specification. May need to address safety and service expectations in this section. Please ignore the presence of the file lock. So so specification one is minimum the subscribe and no fire alarm. It doesn't exist good. Now many more obviously means it try to score back as possible and have a very long specification.

42:29
I've found these that is I mean you don't get into teachers. For instance every elevator in the world has a policy of how moves one point about that later on we get to policy at this point we don't worry about we just want you know to specify two things.

42:55
When safety and the other one is service. That's separate those two subsections. Second requirement services. Just by May you should be many of us. Get the feel that safety means always must be true. What is what? Construct? Like no provide you construct says, all this must be true. Very yeah, this property is always true.

43:31
So the property is don't kill the passengers. You want to don't kill the passengers. Always. All right. So, this suggests immediately suggests think of inbalian relationship that are critical to the safety of the system. So you think in English, what is the safety? And we know that we have some problems, you know, is this these doors don't have sensors.

44:00
We can actually crash the person or tax the dog outside of the floor and no, we know that but I mean no other those things that you cannot have but I'm using the confidence that we can handle specifying. What do you mean by? And in the case of the break, what if the break is, it's got the day without driver will die.

44:23
The safety is not considered, but in this consent from our design, when you don't have not responsible for that aspect, we not gonna be liable for that. We are going to be liable if we press the brake footbed at 80 miles an hour and the cartons of then we are responsible.

44:42
But if somebody cut and cut the wires, we basically were saying it's not colorful. All right, so I understand what's happening again. And the surface is basically, it's going to be required to accomplish something so that kind of suggests that you know, if I press a button eventually somebody should come and take me, okay?

45:11
So that's that's kind of the difference between the beginning, so deciding that there's two specifications, no one, some of the is property. Want to three, four, five, six, seven, eight. But you group property once we five under safety, probably six through ten hundred search. Okay. Specification true says, in this specification you need to factor the presence of fire alarm and then any requirements related to having the fire emergence.

45:46
So to the different state one perspective,

45:58
Inspire.

46:04
Most buildings require you that when when the final arm goes off, that the elevators drops, the first floor and stop, there was open those, that's most building the some require you basically to stop at the nearest floor and open the doors and, and stop there, and then wait for five months to actually manually control, okay?

46:27
We don't have a firearm control. And so the, so we specification is different from, I mean, still a safe chance service. But now you have to factor in the factor in the final. So it's finally, they have strike some forensic button on explore, the elevators coming happily to me and the final one goes off.

47:00
So the power of Michael Scott to the bottom. So you can't tell me that I'm gonna get service because if I get service, the fire is not service. I think the fire is not service so you need to to pay attention what happens when you have fire as a fire alarm.

47:20
So you basically have to rewrite a specification completely because of formers are going to be different because of the expectations are different now. There are related, you know there's no fires. This would be able to satisfy the service requirements and so on and maybe even if it's a fire safety has to still bes.

47:42
Okay? So some things may pay to over but it is not like you replace portion of specification. You basically write the competing a specification, which mail what that is, and maybe different so much, but you need to complete you don't, you don't talk to me about, oh, we're gonna make change one and two and you're gonna be done.

48:04
No, you provide a complete description and as a specification. So specifications, really like this. The firearm is on and you have to behave that. Remember, the normal life? Yeah. Okay. But of course, even this fire alarm never triggers nor my activity should be the same. But like I said, it's you need to actually write a specification completely.

48:36
Not just say this are the difference because if you just write the differences, I'm gonna get confused and make mistakes the specification number three.

48:49
The specification on those three.

48:59
27.

49:10
So here you don't copy everything wrong. Well, these days are particular a praying particular property. T1, you want you basically in here. So there's a cool one here. You basically say P1 is going to be satisfied by p11b to be one like greatness more.

49:45
So these is called a refinement. Essentially, this property P1 from here, everything that stays on shame, but this property could be replaced by this sleep problems. So you say, I'm replacing this property by these three properties. And normally I'll have to prove obligation to show that given these two properties.

50:10
This implied. I can put the property if you want from this department. Now what's going to happen? So this is kind of the president, is that he finally, and this is what I mean. This is what Thomas specifications. People at work. Response. Justification work. Do they establish a journal specification?

50:32
That the last of a lot of attendees so you can do these or that for that, but they're all possible. And then you reduce normal by, putting my visual adding, proper additional properties or channel, defining problems. So in this specification, for instance, you may not worry about the policies of how the elevator moves

51:02
Before you get here, just have 14, provide the properties of how they elevate. So, he started factoring policies. So easy. Okay, for the elephant for me to be waiting here to go down, and for the elevator to come through and go down to not pick me up, this was situation, maybe a lot of permitted, because swapstan eventually, there were comments, show up and beat me up, but no one is starting violence and causing stronger, constraints on how delegate or move and that's okay.

51:48
As strong as the service requirements are met and of course it can put in general for kind of had any service requirements. When we say here, we have, you know, making side of it. A little bit of those all the way and then go over there. All this down all the way up and I love you the best policy but you see the unknown.

52:10
They have the doorways performance and that's why I didn't you know, this is giving something. Question.

52:32
Precious, the physical division, 2 is only compared IRR. No specification to. It's a really big entire specification. One, including five justification, one, ignore the two consider the fire. So therefore it's a little bit. So this is what they finally because we are modifying complete. Now, you can change it.

53:04
I mean, any clever, you might be able to. That is really, this is us this is such a of that is not that the subject of this. So so you could say that this is a specialization of that. So if you have this and you replace every presence of fires true you should drop that to here.

53:31
This is relations. These are specialization of that but to learn on a simple problem and you're making more complicated. And then you learn about properly, financing. How to replace properties. So, most likely the safety properties are going to be the same all over the place. They're going to change the part of the service property is probably the change testing remember here, you only, you don't copy specification, you only identify which properties you are defining and you show how you whether you find.

54:26
Question.

54:30
Some of the addition of the fire alarm, that's not sincerely. Like a saf. Likely not interested. It's you can see the safety maybe. So it's kind of food. It doesn't hold. It's a long trip, separate line item. So general safety constraints. No matter whether it is file or not versus file related to safety.

55:04
So pick up my instagram configuration. Yeah. So it's also safety. But safety. Specializes. The fire not here. Okay, Julia. Again, the general safety is that we don't want people to fall into the wall you want.

55:31
Okay, one. Should we take it then break now? Because we're going to shift years.

55:41
So can you give us example of until

56:21
You so alarm kind of into their alarm and his born, listen.

56:37
So basically, this is an idea, it says two things. If the line is on those same, it can happen is for the. But I was on and so on forever or can be said, that's only two options. You are staying in this type forever or you. Come here. You can't go into a half alarm and visit.

57:09
I feel part closer requires you to get here. So basically, since eventually the line would be reset, Have you sent by the user rightly said. By a timeout. You know, that's a different implementation details but it's a guaranteed eventually. So if we use it to followerhydrone, if we use this to the kill or a list of Well leads to would allow.

57:50
So this is leads to would allow for the light to go into another state and another state and other state. And eventually can be kind of need to be this is no longer true. Oh, I see so we could for instance make it initially. It's a visual line or the sound a lot is it is a solid line, you and then it moves to a flashing light alive, just to one important, come on to something happen, then it goes to reset.

58:28
Oh, so it doesn't. Stay constipating all the time. So I I can use this to specify this kind of intruder. Not always that the until limits it to those two states. So this thing was not one of the elevator. If you use an ideal and one use of, it is a if I press the button, the light is on, okay?

59:02
It's not going to turn off. I'm gonna actually get service, so that's why that less part. The only way you can turn it off is from the churches was a leads to means that, you know, going on and off when it comes. Okay, that's what I want to try to find a constraint.

59:31
All right. Okay, come and break.

59:39
Because they were.

59:54
I think it's or and then just, that's, by the way, that's better. And then we need that variable at the time soon. But types of questions, we found students. I think we infer the type but we need to put it like a very simple type but yeah. And and then our answer, I don't like to reform it or we put the reasons and assumpt.

1:00:31
I'm just actually,

1:00:37
Part where it's a result. What? They don't have an excavator. Spray. It's stupid. But they have. So,

1:00:52
In a more complex.

1:01:16
Open. We're gonna think about that one more. Yeah.

1:01:33
Yeah, I think we have just

1:01:48
Should be about three or six. There's no way to so it looks like real pocket.

1:02:17
You know, really, really helping children church has different team.

1:02:29
They were just visually impaired as well.

1:02:42
There you go. Maybe a few persons on campground. Yeah. Hold on. Hold on. There's absolutely longer.

1:02:58
The problem was that feels like everything. Yeah, I see the proponent. Of course like glasses. I feel like usually it's I feel like usually having my hat backwards make more sense anyway. So I'm really like facing this on. Usually I like to turn away every time eyes and usually my neck will get super sunburned anywhere but I would, I feel like I get socially judged for wearing my hat, this way.

1:03:35
So I feel like I've always got a yeah, I'm sure. No. Oh yeah.

1:03:47
And finishing the above.

1:03:53
One of them that extended. That's okay. That was a helpful extension, a couple of them or yeah. Well, it's about how to resend it since every single group, that was in the city code project, part of it, Can you get it ready? I know the guy that stuff so fast.

1:04:16
I was trying for like a week and a half. I wonder how it was. Just don't don't try to use someone else's. Usually. Okay, exploding. If it's not checked into like a package manager. It's probably not the best. It was like use this random version of C like this really random unique version of C and it would not run on like a computer.

1:04:40
It was like always sick. Well, think that was like how everything it wasn't. Answering the best version. You see. It was like simply GCD with HC theory. That's I have no idea but it's a weird version of feed and I kind of get it to run on my computer and it just kept on saveing every you brush.

1:05:09
That's right. It runs over five minutes. It's not booked it's all hard performance. So okay for the reports which is parallel where goes yeah I think some of these parlors are those ones? It was a good. Yeah, but probably just like anymore for something else. People or GPU, or they argue that.

1:05:32
I don't have very likely with a lot of these ones. They're expecting a lot of things to be pre-installed on. The assumption is that, like, you have something. Like, I try to run. Everyone is like, one of the most important if you wanted to play stick. I never heard of before, and then I downloaded all the children in there, like social good Skytop Scotch with the guys that work.

1:06:10
You know.

1:06:23
Pretty much mobiles and getting you on the market. That's very fun. Pattern.

1:06:39
In of It was very heightened questions doing them. It worked because and then, you know, that's one.

1:07:22
Thinking I have an interview with the

1:07:37
You.

1:07:45
Show.

1:07:57
Really I learned and then

1:08:39
And we don't going up stole that.

1:08:59
With them.

1:09:04
Remember towards our idea of systems and stencils. Yes everyone, every day, just press the button, the 95 is whatever the government outside is. Yeah. Sorry here. It's hard to. So we talked about semester If we like this programs and it's pronounced. We can't talk about that faster snow. Or because it doesn't make any sense because of all the student programs, you know, what kind of marketers?

1:10:04
And some programs need to move to 100 pictures and be able to do another. So, I'm providing people with one. I'm going to be able to compile it on a third activity. So we need to, you know, we need to learn about really on our analyze programs. When you understand, not just the functionality.

1:10:32
As well. When you find more architecture and the question is that, how do you relate functionality there? And that's super.

1:10:51
Control. That's a notation we do that architecture mostly informal pictures and we also get the same informal.

1:11:09
So you know this part is whatever there's other application description. Library is yesterday. I mean, you know, Fort Austin was just completely confident saying he doesn't apply since so one. So that's one important thing about this. We need to think about their mentioning functionality, not contagious and you do that so that basically look at the program and see what type of program is running on what machine So and I can just what do you mean inside the architecture?

1:11:45
The macro artificial or instruction set artificial marker. So for instance, you know, we think of the problem we're going to think about architecture heavy processors, That's one level, Okay? So the However it's another aspect of this from the work of unity which is, they're all that one, for sure.

1:12:10
That you can actually this approach and no matter what kind of argument. So we're going to basically look now at different architectural styles all the way down to gateway. So we started the macro and we go into the instructions application and so justice. I mean that's part of the kind of the argument that.

1:12:39
Well, this is journal enough to be able to recover everything that we ever going to do. I should mention in persons that in the past, I worked with another is another system of CSB compliance, suppression processes, and I actually hit this thing five in four months. So basically,

1:13:10
So I could in that system, I could prove for instance, that your program is going to run out of them for that never happened or, you know, any other properties that they could talk through the resources. We're not doing that here with stainless informative. So I tried to reduce one is today and civilization between programs and architectures, and two hundred explore the range of architectures in how they relate to the.

1:13:48
And that's because of the two major scenes I tried to put. So look at different diabetes. So further the very first one is a singularness. Sure.

1:14:13
So in this kind of architecture, we have a fixed type of processors, fixable memories and the other access drives. So typically we have something like this.

1:14:30
That's why this picture I'm going to go on the station here.

1:14:37
So this could be memories. It's gonna be processed and maybe there's a there's a communication mechanism communication mechanism that allows processors to get to memory. So, these are CPUs, these are memories. And and there are accessories which are red. They were allowed to revert, right then particular memory. So, what we're going to happen is that when you take our program, the program consists of statements and variables.

1:15:14
Right, we take all the variables. And so the year they've all experienced. And so, then that's enough, I'm responsible for the right of the story of on all the memories place, because there's that three, the memories right here. So you will, so one copy in here then. Well, we have Access.

1:15:51
So, if this processor has a right access to this memory, it can rightly, but it doesn't read. Answers can never read anything and that way at all. So what you mean that is your only one rebel wally. So the one thing correct. So if they can be variable and they put you take every statement now we've seen later on.

1:16:24
I mean, in this case, if we have three statements

1:16:35
Okay, we could put this one here, just to there. It's and you could also which is true in the sleep here. That's a mapping. We we can make those decisions and look at the concept as it's of those kind of decisions. Now, let me look at this to statements the statements, what they believe in modify variables.

1:17:09
So stainless tend to be x called equal y, right? That means that the process of this isn't extended has to be able to write access to x. You know, read access to storage now. It's something ever raised, right? So, so you can have xy.

1:17:34
My okay, the processor doesn't need to have a right access to why. You know what it needs to be three guys. Just watch because you read the value before. Fine to computer index, and you're writing it with x index of properties by that value. So you usually have access for the for the forenses, you have to have redises for the variables.

1:18:09
You can have read or write or you can advose. So if one is setting, you have this, then you have to have read access to x and 12 not just y but definitely need the right answers to X. So we can take an example.

1:19:02
So because that how many? That and minus 1 statements here. So, we can allocate this n, minus 1, segments to n, minus 1 processes, and then allocate themselves to social change. Again, do it in minus 1 or 2, right? And memories. So you could force yourself an architecture where for, as an example we can have A here and it can have process.

1:19:41
I need the same mind there. The process is basically just payment die, okay? So the eyes one is process one, some process one, it's a one called an equal maximum A1A1 plus. But and then another process is So you see the OSHA this memory and the old have access to the.

1:20:10
It's one way that you could be done, another way we could basically have this process outside there. So his VI is PI plus 1. It draws his own local memory. So, PI has still AI the iPass on yourself. A high plus 1 and VI is going to read from the plus one.

1:20:43
So it was that way, which means that in notice AI, it's updated, right? But it's also there. So it needs to have big right, access on AI but you don't really need to have read access when I have. So this is going to be distributed in memory here. We have a centralized that most consistent.

1:21:09
So, if not only immediately obvious, how you take a statement program and what architecture should be using? Here you tell that the statements are allocated to the processes. Who doesn't you? What you do the configuration before you load the system, you do that. Okay? This part of the loading process, I mean the program language may have mechanisms to do that.

1:21:40
Okay? Like, for yourself, something you have scoping mechanis the five new scope I'm working parallel with, You can only see them most recently. So that's can be done for programming language that can be done with my system that issues is not in load. And you can impose I mean the operating systems can impose restrictions like a process when they given maybe allocated to the piece of memory and generally if a process is a memory, it will be.

1:22:19
But in most of the allocated, another piece of memory in a write, a read, the only man. So that's and those can be done at configuration time in you on your own loading. This.

1:22:35
No, what if we replace this by final box?

1:22:53
But he knew anything would work because community, we read everything computer, everything right here. So that so that first approximation, but that's really the specific. If you're using a job terms, in order of what a child above the allocating is kind of memory. We would have to basically do a multi-face implementation so that essentially the mapping.

1:23:27
Thank you. Very the way we have to map it. Is that everybody that we face, then it went as a computer phase and then everybody was right, first change. If we do that for don't have to coated that way. But you need to think in terms of the mapping, if we go to the single mapping that right?

1:23:50
Then we could be allocated.

1:23:57
But that's kind of very specific to that is in the unity. Would have to have multiple and super computers can do that. And final computers, who met was networks? Most networks they all of you. The work exactly like that. Everybody every processor is given a chance to read for long or multiple memories.

1:24:22
So, the network of goods and everything process rights, and there's a right conflict. It's a because little careful on the. So this is a synchronous share. Any questions is what you normally see on a processor. This is what we'll see on the multicore. This want to normal see on the local internet network, do something systems that we have.

1:24:58
And if you give people that, we take a specific system, you know, we can figure out how to how to use this general principles, you know, to be able to model it in allocate, our programmed with

1:25:25
Time. Now, when I was about architecture, I negative this coverage and that's the kind of market that is common to us is the system.

1:25:49
Where I just, how does this work? Well, you have processors.

1:25:57
They had their own local memory. This is in Philadelphia. This is that, and there's a network. And the way, the top of each other is by sending message. You know, that's what makes them in touch. Messages is very, extremely high speeds have a message. I'm broke and having to pack it as long as it's implementation detail there.

1:26:23
The essence is that you are basically sending the message someone else. So there's a difference style of architecture. And so why not some of the problems as well? One of the things that we have in basically have processor and local memory.

1:26:48
And we have chance.

1:26:53
Try to do this for an impression purposes. Now, in general, we assume that it's not my fault, first came first hour after that, huge messages around me. So if this processor sensor message to this processor, and this is another one, they are assumed to arrive in order. That's fundamental to the stupid systems monitors.

1:27:18
That's not really true on the internet because the two messages could be coming on different routes but then they didn't give you order within the destination to make sure they are. The semantically are correct. We assume that there are no way any the channel is doing directional findings. Like this, that means this processor must have right access to the channel.

1:27:45
And this process of I have read or writers to the channel. Why I'm gonna read this? Clearly, the message, why, right? You move the message without using the messages when they write answers. Okay. So how do we model as well? The interesting thing is that, I mean, that's not the way we write overload, our code.

1:28:19
So we want to someone that does a validation. Clearly statements are allocated on the process course. Clearly variables are located in the processors but then we have channels. So jealous. I did a special day that I needed for communication and the channels that shared all because to processors like that.

1:28:45
So what what really happens is that the, in order to work on them the channel, we need to, to have a sentence to write the code in a particular pattern. So can be allocated to, we basically need to have equivalent of sin and we see and the way that's receiving channel.

1:29:14
Hey you.

1:29:21
So, the channel is not full. You can add a message to the channel.

1:29:51
The challenge about emptying you thinking the head of the channel and assigning to x the mocker variable and in the tail. And the sending back to itself, These are the same from this are basically modeling. Sent send them, you know, send and get operations on the channel, but that's what it's really saying is that.

1:30:17
Yes channels are dreams but is variables are 10 wide shared. And the only way you can talk to this variable is just like this, You can't say SQL and equals 0. You can say C colonical C, square, or C, colon Eclipse, camera Y, whatever you want. You can't do that.

1:30:43
This only pattern. So this is the panel if you have to use able to actually communication. So what was the he if I have a QC? I can add it into the cube, okay? And had means that they I take the first one like the head and this is a film case.

1:31:15
Tim stay over. Okay, So so this is specifically telling about the need to write our code different. We can just automatically map our code to this architecture unless you make some adjustments. So if we think our previous statement, so we had logs high

1:32:15
No, this looks like a statement but not this, it's equal. It's because I assume and is the same as needle and floss is modern. Come on in.

1:32:39
Okay, so we understand what is dementia is actually it doesn't need an election.

1:32:50
It takes a larger tone to numbers. So, each one they have a unique ticket, there takes a larger to. And remember, now this tickets can be, actually the initial index values and iPad is better. There's a lot of computer and eventually everybody sees the same scene down. The problem is that this is not going to be allocated to that architecture because doesn't follow the rules of that argument.

1:33:24
In that architecture, we have the channels. You know, each other here, and we have to the channels. According to this, he watches and look at the program. Do they? That same place things and there's a maximum everything. So if you are in the street share the seven and ever one and we keep on doing that, eventually all of us have a seven so we know that she's a leader of.

1:33:53
Yeah, that's a little. That's why. And making them. So this doesn't work because government form So in pretty fine. So, this is an example of different kind of empire. It's called take one program and modify it for other purposes and to get any program that has synced by the same thing right now, different way.

1:34:25
So so this is the same program one. Now a program, two.

1:34:43
Pain. What you're going to do, here? We are going to not allowed this direct access everybody. Use a channel immediately. So taste of eye. Come on. See I cross one so CI. Plus one is a channel coming from the five. Plus one process gets excellent of Azerbai and the head of see plus 1.

1:35:35
And this, it's detail. See.

1:35:47
If?

1:35:55
In the channel is not them.

1:36:06
So now this agrees with formulation that we have the requirements Now, no statement. Basically, no way we access the channel is by moving the head between copying the head. And he moving ahead from the, from the channel well and following can follow them.

1:36:48
The.

1:37:20
What's happening here? Is that the channel that we send on out on give we augmented because all kind of value and you do this asynchronously. But sometimes we read the with the previous channel and I've been on maps sometimes with center and you can prove that everybody that Now be The problem with this solution is that it really send me message all the time.

1:38:04
So, it hasn't changed when I send air again and changes here. Again, again again and again from again again. So it's not really maps to the architecture. It can be implemented computation but it just sends from anybody. Okay? You know, correctify that

1:38:40
ALA. Everything else, the same?

1:38:52
Same table processed.

1:39:48
What we did? We had another variable being and whenever we send about you. So this is what we're doing here, we're sending the value. Our value very good aid on the channel. We also update B with that value, So he's the guy who hasn't changed, He's never fires. So now we're cutting down the number of messages.

1:40:18
We're sending out, but only sending a message out when we actually have something meaningful to say, we actually send out them even and event. The valley is the same old. We don't say.

1:40:34
So, yeah, and you just take a CI times AI, okay, nice? That of men and then congratulations. Yeah. Let's talk about the next and that should be a fact to

1:41:04
So that agrees to its this former. So now we can map our system for those questions. So does I? And I plus one has to be neighbors. Well, there's something.

1:41:39
Using zero. This is one, which is two all that's like this would not just come. So if this has, let's say 22, plus 17, and this is 6, and this is 4 eventually, the 22 close around and everybody has. Oh, so that's why you brought a map there. Yes.

1:42:07
Oh mom. Is that modular makes it no maximum value. Oh the the thing in the circle plus and well. So bas assuming that the memory used flats here, whereas glass modular? And, oh awesome. I, we just made that perception and that's why I want to do three plus one.

1:42:39
You can see Paul as possible.

1:42:48
And I have a questions.

1:43:02
Now, both of us architectures, how do you synchronize? Your I have a question here below that thing. What is that in the circle plus here plus? Yeah it's an assumption that I'm making that want to use. Plus use plus margin of a, it's my dad.

1:43:39
Okay. The most of these are asynchronous architectures, so they run with their own their own schedule. We can also have synchronized architectures.

1:44:15
But they have one common quite to their own work of the same can think of. And basically one instruction.

1:44:40
First step.

1:44:53
So it doesn't mean that everything and I could process. The synchronous, You can have one statement and I was a statement was a boxing between the boxing between. But each statement once demanded executed in the same in a single step and that execution can distribute across multiple processes. So there are connections for itself where you have the same code, some multiple data streams, single instructions architectures.

1:45:33
So in the same code in every single process of a thousand committing processors for, they abused different data and eventually they all get a signal to execute fraction of that code that's ones that and then they get a signal that you could not afraid of. Now, in those kind of memories typically, there is also something called the basking process.

1:45:59
If you don't want some processor, they execute in a particular step. Then you turn on a mask and basically turn off the execution of that process could be globally set up that way or could be the processor itself. They have some logic were based on its state and besides that, but anyways, hey now the code and linear.

1:46:30
So they go being one part of the code being the next signal. They're actually, in our case here, actually allowed them to take a different difference can. So you've been having for this one has two products and three box this four as five. So, the processor can make one, another one is still, another one is three by the one of the same step.

1:47:07
And then another step we can execute this form is five.

1:47:15
But that's what this kind of architectures do. So,

1:47:24
Big two examples here. Let's go back to the previous example. So we had the, you know, the way the box, I

1:47:55
So if you take this example, we can match it when I be future here. But here the memory is a and then and each one executes step by. So if you want me to begin or part of each, one of this, every fragment of a statement is exactly quite different processing, but you can also have something.

1:48:29
Let's say they want or an equal.

1:48:52
So in this case, we're only opinion anymore and this is all done in parallel. But what's kind of crazy years? See what I look at this statement. We know exactly what peace goes to though. Mapping is pretty large. You think that ice touching eye and this segment corresponds to physical processor eye?

1:49:22
It would have different rules. But it still speak obvious that those things are the pieces that you can allocate here and it's not obvious, you know? It's really happening here. Is that, you know, we could have for instance, a number of processed source.

1:49:41
And yeah, the memory values. And what we do the first step public like this.

1:49:58
The second step have been like that.

1:50:07
So it is. And so there is a, there's a mapping to singer's machine but it's not being novels to make it obvious. Why we have to do, would have basically, to decompose rewrite the program to make it more corresponding to, this particular architecture. So I did, it's not all.

1:50:32
It's obvious. Have to sing about it and you don't have to be either ghost, you should know that the compiler could do it. So, as long as you know, it is really, you know, can be that to this other way that particular architecture course questions. What I'm done means.

1:51:00
I'm the maximum device. All right, for every eye, you compute AI. So it's a 1, a 2 is 3 a4. And then you take the maximum of them and that's it yourself. So,

1:51:27
I'm in here. You are greeting AI and also rights to AI. Right is right into only to A1. Oh, A1 sorry. But you are also reading from a 1. Yes, because just imagine, you know, what kind of so is this program deterministic? It's all. Well, that two things here.

1:51:56
This is what this program is. Yes. Okay. So if we have a one, a two hasty A4. And this has 12 this is 16 and this is 74. Just okay. This says for every value I compute HRI so these are the values of a subi a1a2 is made for, right?

1:52:24
Yes. And very says, thanks a maximum have one of this. So this is 74 and then it says thanks to 74 in, put it into and no notice it. This is one statement, one instance, by naturality, it's not going to be time to be implemented. Oh, so takes longer a lot of end steps.

1:52:55
Try to get itself and I put the result in question to actually put in the process of that. There's a lot of channels, right? Those connections. No, I'm reading these two values and computer maximum of them. I did, this could be the maximum and I did these two values about.

1:53:18
So this process on this can have access and initially process 21,

1:53:27
City form. As long as put everything in

1:53:38
So, the value of a 1 is only updated 1/2. Pair wise comparison is all done, entire comparison all is done, but the way to be compiled, would be compiled into login steps or So this completely transformed by the compiler in another program, which does this. Oh, all of it.

1:54:09
Kind of divide that program every day before product.

1:54:22
All right, So so far removed had architectures, of course, going to, basically compute, large computing, machines networks decorated, and, for us. Okay, you need to understand. Those are standard use. They have, you know, if you have to become algorithms for them here, to understand others of those architectures work to develop that action for now.

1:54:54
Let's drop down the very bottom. Every every CPU, every processor that you can use, this is what and the lowest level. He you speak marketing. Oh we're gonna go to that to make it like there's a lower level than that. Well yes it's upstairs some says that I bought the same level but logically exactly compute things when I'm trying to talk about is you know, by the CPU placeways.

1:55:31
And what's the registers. Yeah, so you are on the right page for just five to separate history. So graduates.

1:55:43
So most CPUs basically never back over registers, and the reason they handed back registering because they're very fast. And they come also they can specialize so I can be any register for various exceptions. That's handling it. Very interesting in all kind of stuff. And so, you know, some kind of the next, then you want to talk about it.

1:56:12
Okay. How should we think about resistance? How we understand about registers in a very particular way. We think of that register as being a topic. However, people have started registers, you know, but I'm not afraid. So nearly they came up with three classes. Say regular.

1:56:41
Why is this important? Because this is cheaper, think of? And this is the cheaper thing. Yeah, it's the hardware level all the way the button, but this I still cheaper. So if I can use this kind of registers implement the register above, so then maybe I save time. And also, I think, you know, computer scientists want to understand fundamental relationships.

1:57:08
I mean, how are this related features? What do they mean? So, what do you mean by? You know, this is what you mean by like cosplay is or what type of gains you have to use. Also, on the control market how many clocks made to. So to explain that, let's do the form and we wanted to and here there is a weed, followed, by another way.

1:57:42
And then there's the right, you guys. They can see hero. And and there's another right.

1:58:00
To things are kind of out of the register to

1:58:10
Okay. Now, right cannot that assume that they can never that neutral expertise grace jelly with you that they can. They don't have to be released. So and they write these could also have a laptop. So here's a distinction between the three types of give us a sign of register.

1:58:39
So everything is measured from what you read for others. So it's the same register I read and overrides a letter and write. Can you turn any value in that place?

1:59:00
So, you know this the register was zero. Here it is. True here, and in between was one. This is over loves is right and could return the phone.

1:59:24
That's what the significant Any valued that is from the register would be would be an example of that's where the safe exercise. So, you're gonna ask me how in the world same here, one morning, zero one.

1:59:47
Is right, focuses 0.000. And then we to 0 0, 0 1, and then move to 0.

2:00:05
So we're not as how in the world. Do we possible in a physical system? What I change this one beat to from 0, to 1. I can get a 4 but part of the reason is that it depends in what order be some frequently and unread. So it's possible that a wide starts happening in the register from left to right?

2:00:36
And the reading reads from right to left.

2:00:43
To be home or not, you know, going to get the right of the number that before or after could get any any arbitrary number in the register. So yes physically this really possible to have depends how the electronics work in terms of reason rights, how they do the leader.

2:01:04
Don't understand that. Now a red rotation basically says, you can get if you're override or conducting with a read and write, sorry for review is overlapping overlapping with a right. You can get only the previous to them or the next value, you can't get undergrads. So it's nice. So if this R1, we are talking about the regular berry canister with R1, however, absolute this could get a zero and a one are two over.

2:01:43
And after this could get a zero over one, but those over after this. So could get a one or two. If you're only getting value drive, the highly completed values, you would get the older than you. Well, the problem is the following, this could get one in this Brazil.

2:02:16
So I read the four was another read. Maybe getting older value. So, the order of the rights is not preserved by the regional regular region.

2:02:31
They told me register preserves a door. So if this is this, you know, get a zero one. This finish again. So these are one eternal zero. This can get a zero one or two if it returned to one, this can be only the one or two, you know, terrible time.

2:03:01
Why is? Because logically atomicity means that things happen can be reduced to one spot So this right can be reduced to one. Place is right to be used to one. Place is read can be reduced to 1 plus or if it is used to apply here. We get a 0, okay?

2:03:32
And in this case because of this is here, this is there can only get a zero. So I thought recently it's really and this is what happened in database or you do a transaction. You assume that nothing against the world happened? It takes two days to run this transaction to find out, you know, the national debt but it's woman.

2:03:59
It doesn't. Now of course the student databases are designed in such a way that you can manage other the same time. But the effect is as if they are done in an instantaneous subtype and never overnight, that's the criteria consideration is criteria. Or correct implementation of distributed database. Everything is transactional single almost Singapore is a and so you can see that, that's why then the economy is that they just exagger on those things.

2:04:39
It's everything accessible to things. Now where the instance happens is not the definition. So see I said this and that but I could have done it this way and then I wanted the one instead of Missouri, but I wanted our truth. I'm not going to to be able to view out because inside is the things.

2:05:07
It's been having fun actually analyzes holding. I'm an irregular resistance. We need is even possible because it is impossible. You should try. Okay. So the other thing that the next question will be all right if we do this? Can we actually not only because there's a unity and that's what it is.

2:05:41
I mean the notes I'm providing the formulas. There is basically what to do for every forever, right. You have a variable to begin on the inside verb in. So maybe one and one, two and two, they can three and three and then the right is happening between the register.

2:06:05
And for every read in the same scene, begin read and read and then read half of the interview and then you can write for a properties, like one of the properties, no. Two rides can overlay, if not the right number that you cannot have a begin begin and no ends.

2:06:26
And then the previous you never been a state like that. He started to begins and they don't have at least one of them, imagining it and I performance specifications, and you can write the code to simulate exactly the same regular. And, and, and that time events. It's very powerful five that you can get on any questions.

2:07:01
You don't need to understand, sorry that code, but for us, but I think it's very important to remember that, you know, the concepts of safe redware and product because they may have implications in others in other settings.

2:07:32
So we know if so you said that we can use a fair resource to build the regular one and the regular one to build the other. I would have to go back to the, to the theoretical just and study that theories, that all serious of serial entries. Tell you, how many registers of this kind need to.

2:07:55
So that's the mean I don't have the top of my head. Okay. Okay. So the third one is much memorial than the other one. The safest easiest thing. The question that can implement the others and normally you cannot implement. It is, I mean, it's just one register. You need combination of righteousness.

2:08:18
So I mean, I don't, I'm not waving my maybe to get the regular register. What to do, you know, you have to save registers and then maybe Julian. And then on the right, the right toward register and really read on the other one and then you fit the program.

2:08:42
So you change which I say reading and so this will be separated rights and you can get an effect of a of a regular but I don't remember that. Theoretically so so the register here, is it a synchronous where you have a clock sync, six? Oh, something that you can read and write.

2:09:06
Oh, that's the only definite thing because when I started register, they have classing signal and they only have a clock in the clock, basically, comes the data into the register. Yes. And if you have a clock, but does that mean the register is atomic? Oh awesome. But I mean in this case, we're not 145, there's a clock on or we're basically just looking at, you know, these are the two operations we can do the operations take time.

2:09:47
Oh, so it seems overlap in time. Oh so we don't need to know the exact time. But the question is it was an overlap or not. Oh the overlap of the consequences of the owner all of it. Oh okay, no. So this one general architect from patterns standard things and then a low level kind of example of Well, the other things that we can it doesn't study validation.

2:10:23
And what about point is schemas

2:10:34
So schema is very patter and if you so the set of rules and if you hold the rules, you are guaranteed, it's a compiler, it's going to map your code to this item.

2:10:55
And the scheme is basically set of rules that lead to a well-defined lacking girlfriend. So, this takes on the examples of

2:11:10
Read only.

2:11:16
So that you don't need schema. Basically, the rules that we have shown. Thank you for each variable. This video right now.

2:11:35
By only processor. That's a fundamental constraint and you can look at the code and can tell, is that the case or not. So for this we write something like like this is process on one person three so we have

2:12:06
Majority of BMC a plus 1, plus one.

2:12:24
That this program. Satisfies this requirement, this room. Well let's look at it. A is written here. That was nobody else does be is even here by processing or whatever sees it here by crossover one. So majority basically says, if two two of the values are the same, then the value, that's a value that is communicated.

2:12:52
So, So this. So this is one and one and then becomes one and this is zero and zero, that's what the majority says. So, choose opportunity now it's not. I mean, normally this is used as a zero in ones. So normally, as tall as defined,

2:13:18
So if you use this kind of schema, you can even, I mean you can just basically read create the variables, read the variables, anytime you want.

2:13:37
So, you basically,

2:13:47
Okay, so let's take two cases.

2:13:52
Since you are the only one that's rights, don't be very like the reading as events. Now, if you are only reading one value that they shared from the disowned by some other processor, You can read it anytime and you're going to get consistent back, keep reading two guys. Then the problem is that if you read them at different times, you're going to to get inconsistent state.

2:14:23
That's the values, may not have this never together this particular vehicle, so I should need to. Do you need to do? Basically come up with a deadlock free mechanism for him in the valley. So basically we love the values so you read the values now for medical order so he logged in in that order and then he released it.

2:14:49
So it's very basically the United think about any of the on this properties. It's automatically the compiler could do that for you. So compiler could see that you're using?

2:15:05
To not open with. And then we're basically.

2:15:13
And then we are updated 21.

2:15:22
So that's a really long history.

2:15:36
Okay, still variables.

2:15:52
These processor has a promo code that can be done, right? And,

2:16:00
So you can already name, one share rate.

2:16:26
And get right access to one single share better with for statement. So what you're going to do you're going to have to structure and get that's only by somewhere else. So you're going to have to basically get control of that day. So where you get control of that variable, basically you send a message and says, as well, why say you talk to the value of rights value and there.

2:17:05
So it's basically, you know, because you are only practicing one single variable that does not belong to you, and the system of the magically can build the product, called to put the lock on the variable, then you are not really right. And then release alone. So keys here single so you can edit on the left.

2:17:39
You connect from the right now. If you look at this code here, that doesn't satisfy that problem, because accessing more than one variable owned by somebody else. Sure. If they notify, basically, you see communication, jurity x y c,

2:18:08
X squared equal. A one B. So each standard Tony may mean one variable that is not local.

2:18:23
But you could also obtain it. You don't know. I mean, here's if you want to see. So it's a big area, but you'd have to modify the code to one like this in order to meet their share. Very again, the key to the schema is that it provides. If you write in that style, it provides you.

2:18:45
The strong guarantees without have a mapping to a organization. Well, look at another scheme. Another schema equation.

2:19:08
So by the way, there are English equations equation, programming language. The programming languages in which instead of saying, if they're now blah blah blah, do our blah blah, You basically even consideration and the system solved equations. They are actually programming languages compilers and other systems that work. Exactly. Okay.

2:19:35
So now if we try to relate it to the unity, the way to is going to do, it is basically already have is important section.

2:20:00
There are no that no assignments in the program.

2:20:07
So, for instance, we can have something that like

2:20:17
Sequel. Next, why? This is the normal section. You see it's an equal and not colonical parts. Simple for

2:20:38
That's done. That's the whole program. Just a bunch of equations. So the equations to take a and then you solve. So for x by taking the value. So for y's the same value b. Any so for c by using x and y, that can be computed. So the way to, you know, one way to actually do this is to basically order now.

2:21:03
For example, this is one to and this is three. And so, you can see this program can basically rewrite it that x colony called. So the compiler would have to do it for you x coordinate, or a y or an equality v secrecy, max of x y, but you want to order them executive and disorder.

2:21:32
So, you have to have a flag if equal 1, if that is equal to 2 and people think, and then when you do this, now you have to adapt all the plus 1 and and plus one. And then so that's what the compiler do you wrote. Since you don't correct, program strictly in the honor section, we know that it has a solution like this.

2:22:10
So that's an equation of equation, schema.

2:22:19
Another schema circuits.

2:22:36
Basically about life programs but they have to have particular so you can't write, I was ready? Arbitrary code. So, for instance, you can write a program that corresponds to gates connecting your kids. So you look like this thanks for Nicole, F, see on Wi-Fi, or it's going to be one or more videos.

2:23:08
So this is correspond to or and not an F to be depleted by those so that we exactly on the logic would be exactly that of your and any more market, then you can have registers.

2:23:34
And their atomic, see you on a call are mixed and I see

2:23:48
Have x.

2:23:55
See.

2:24:01
So basically if some property be that it satisfies, then you have the other register in. The property is not true and you don't have so that will be the pattern that you've used that. You can have the majority ele. And by the way, all these variables start binary.

2:24:32
01. It's only an obvious correct circuits so it's only the majority of majority of x and y and c. It's a commonly used gate in system, circuit design and otherwise a frequent.

2:24:59
So, you basically have C1 C2 correlation, power comma, S.

2:25:12
You are on this.

2:25:34
Secondary subjects. Okay, so

2:25:45
So this is kind of pattern that we have to use, but notice here, it's an event. He says that you cannot have the set and he said at the same time there's fundamentally insurgent. So how do we say that to say by state in any value? But it's very interesting conceptual intellectual on our schemas so far.

2:26:11
We're syntactic schemas. I told you the rules on how to form the program and the compiler. Automatic. This is not syntactic. This is cemented. You have to prove that your circuit is a correction have to prove that this is never happened. That doesn't end up can possibly all the other proof properties of the logical properties that you had used to.

2:26:43
They apply and the last thing I'm only managed to mention it. I'm explain to detail is the

2:27:05
One of the problems with chips is a fact that they are caught Well, so you're getting some better bigger and bigger and bigger and bigger chips. What happens when you get big chips, if you have to distribute the clock further and further, and further, further away These signal, I forgot.

2:27:28
One thing is that one? Thank you.

2:27:33
Why have any require that's the way you model way? Just so the circuitry. So the problem is transfer decreasing. We have to distinguish the clock Is that very schemes. Now to distinguish the clock from multiple synchronized products or whatever, sinks like that In the same circuit basis, there is no problem.

2:28:06
So the question is how do you compute whether it's not like idea is that you have to design the subjects in such a way that no matter how long, the wires are no longer, hold on the dessert and the layers. They always do the same thing. So you can take these circuit, they just wire between these two components, running to painting them back.

2:28:28
They can learn multiple mini settings, but the behavior does not change and that human is unable to do that. Without clocks have seen much and that people in country design markets circuitry and the winding fast. Now the most circuit designed they are still crossed circuited around the, but like I said that, people have done that together.

2:28:59
Faculty horned. Organist Phillips. Is these eyes discussions. Don't be different way of designing things and the issue there is a semantics again with this anatomic relationship here. Have to prove there is no way. That delay affects the result. And the way you have, the way you accomplish that is anybody having feedback rules?

2:29:25
So you have to have basically conditions that make sure that I don't update until you have done updating and there's an example of per to here.

2:29:48
Yeah so here but it's always three and yeah. Also this is my favorite one. That's it. That's the consistency now. So this is a song uses, but there's only one, it's computed automatically so forever to use all this. I mean, you start available on the player. You don't have that.

2:30:36
No assignments. Dam. You only have always so crazy is definitely just something else and the last one has a final so it's like you don't have you don't have library you do that, you may sound distortion please. So that is have to restore something else. Oh,