Talks and presentations

Computing Certificates of Members in Archimedean Quadratic Modules in \(\mathbb{A}[X]\) and Certifying the Emptiness in Inconsistent Monogenic Archimedean Quadratic Modules in \(\mathbb{A}[X_1, \dots, X_n]\)

March 25, 2026

Talk, Thesis Defense, Albuquerque, New Mexico, USA

Polynomials have been found to be a powerful tool over hundreds of years for modeling problems in numerous applications in science, engineering, medicine, and other domains; convex optimization, as an example, has many applications. In the context of formal methods, polynomials arise in modeling in aerospace software and robotics–especially collision avoidance, cyber-physical and hybrid systems, autonomous vehicles and controllers based on neural networks. Optimization of a polynomial function subject to polynomial constraints is investigated in many areas–to mention a few, scheduling, resource allocation, financial systems including option pricing and portfolio optimization, quantum information systems, control and system theory, particularly analysis of dynamical systems such as stability, equilibrium, and more recently, in sophisticated modeling of neurons in deep neural networks and machine learning. Modern SMT solvers and theorem provers often resort to linear approximations of polynomials as a pragmatic solution due to the inherent complexities associated with reasoning about polynomial inequalities.

Slides | Video Presentation

Computing certificates in compact quadratic modules in \(\mathbb{R}[x]\)

September 13, 2023

Talk, Thesis Proposal Defense, Albuquerque, New Mexico, USA

This thesis will study algorithms to compute certificates for members in compact quadratic modules in univariate polynomial rings and certificates for the Archimedean polynomial in the bivariate case. Our current results compute exact certificates (sums of squares multipliers) that certify the membership of a polynomial in a compact monogenic quadratic module. Our method is constructive and symbolic, thus exact. We provide bounds for the degree representation of our sums of squares certificates. Additionally, we compare our method with existing solutions involving numerical approaches. We plan to extend our methods to the general case of compact quadratic modules by finding reductions of a general compact quadratic module basis to a single generator that is included in the original quadratic module in consideration.

Slides

Implementation of Uniform Interpolation Algorithms

October 20, 2020

Talk, Master Thesis Defense, University of New Mexico, Albuquerque, New Mexico, USA

This thesis discusses algorithms for the uniform interpolation problem and presents their implementation for the following theories: (quantifier-free) equality with uninterpreted functions (EUF), unit two variable per inequality (UTVPI), and theoretic aspects for the combination of the two previous theories. The uniform interpolation algorithms implemented in this thesis were originally proposed in (Kapur 2017).

Slides

A new interpolation algorithm for the theory of Equality with Uninterpreted Functions

September 09, 2020

Talk, Computer Science Colloquium Series, University of New Mexico, Albuquerque, New Mexico, USA

An interpolant for a pair (A, B) of inconsistent formulas is a formula C such that: A implies C; B is inconsistent with C; and C only contains common symbols between A and B. Modern techniques for interpolant generation rely on special deductive calculus and unsatisfiability proofs. In this talk, we will discuss a new algorithm to compute the interpolation formula for the theory of Equality with Uninterpreted Functions (EUF) that does not require unsatisfiability proofs. We will discuss an observation made during the implementation of the algorithm, introducing a new Horn-unsatisfiability algorithm that uses a congruence closure with explanations as the mechanism for equality propagation.

Slides

A Single Proof of Classical Behaviour in da Costa’s \(C_n\) systems

November 01, 2014

Talk, Ninth Latin American Workshop on Logic/Languages, Algorithms and New Methods of Reasoning LANMR, Valle de Bravo, Mexico, Mexico

A strong negation in da Costa’s systems can be naturally extended from the strong negation \(\neg\) of \(C_1\). In [Newton C. A. da Costa. On the theory of inconsistent formal systems. Notre Dame Journal of Formal Logic, 15(4):497–510, 10 1974] Newton da Costa proved the connectives \(\{\rightarrow, \land, \lor, \neg\}\) in \(C_1\) satisfy all schemas and inference rules of classical logic. In the following paper we present a proof that all logics in the \(C_n\) herarchy also behave classically as \(C_1\). This result tell us the existance of a common property among the paraconsistent family of logics created by da Costa.