# CMAFcIO

## Some aspects of geometric control theory

Por Fátima Silva Leite (Universidade de Coimbra).

## On the undecidibility of type inhabitation for atomic polymorphism (part 2)

Por Clarence Protin (Independent Scholar).

Abstract: Pawel Urzyczyn has shown how to obtain a syntactic proof of the undecidability of type inhabitation for systems $F$ and $F_\omega$ by a reduction involving the codification of a certain undecidable $\forall,\rightarrow$- fragment of intutitionistic predicate calculus and the use of the Curry-Howard isomorphism. We show how this technique can be simplified and used to prove the undecidability of type inhabitation for atomic polymorphism.

## Uma conversa com …

José Matos (Ordem dos Biólogos)
Fábio Chalub (Sociedade Portuguesa de Matemática)
Carlos Braumann (Sociedade Portuguesa de Estatística)

Moderação de José Francisco Rodrigues (Ciências ULisboa)

## Solvability of the thermoviscoelastic model of polymer solutions motion

Por Andrei Zviagin (Voronezh State University, Russia).

## On the undecidibility of type inhabitation for atomic polymorphism

Por Clarence Protin (Independent Scholar).

Abstract: Pawel Urzyczyn has shown how to obtain a syntactic proof of the undecidability of type inhabitation for systems $F$ and $F_\omega$ by a reduction involving the codification of a certain undecidable $\forall,\rightarrow$- fragment of intutitionistic predicate calculus and the use of the Curry-Howard isomorphism. We show how this technique can be simplified and used to prove the undecidability of type inhabitation for atomic polymorphism.

## Why do mathematicians study differential equations? Can we solve them? Are they useful?

This talk is an invitation to the magic world of (partial and ordinary) differential equations. A (partial) differential equation is an equation that contains an unknown function and its (partial) derivatives. Such equations are used to describe a wide range of physical systems or natural processes. Examples include many aspects of our daily life. Partial Differential Equations also play an important role in several areas of mathematics such as analysis, probability and differential geometry.

## On the elimination of arithmetical comprehension in proof mining (part 2)

Por Pedro Pinto (Universidade de Lisboa).

## Asymptotically sectional-hyperbolic attractors

Por Bernardo San Martin (Universidad Católica del Norte).

## On the elimination of arithmetical comprehension in proof mining

Por Pedro Pinto (Universidade de Lisboa).

## Papel, Dobragens e ... Matemática

O que é a dobragem? Só uma série de vincos?

O que é o papel? É bem conhecido. Todos o conhecem.

O que é Matemática? Há quem diga que a conhece, mas realmente não. Há quem não queira confessar, mas realmente sente a Matemática.

Para mim Matemática é um modo de pensar, uma maneira de ver o mundo, um caminho para compreender o universo, uma estrada real para quem quiser compreender.