From the 1 of 13 linked papers with an AI index.
11 papers · 1 filter
Conjugacy languages in free inverse monoids
André Carvalho, Ana-Catarina C. Monteiro
We initiate the study of conjugacy languages in free inverse monoids. Motivated by the notion of conjugacy languages in groups and the study of conjugacy in semigroups, we introduc…
The Post Correspondence Problem for free groups is undecidable
André Carvalho
The paper shows that the Post Correspondence Problem for finitely generated free groups is undecidable, even when one homomorphism is injective, by linking it to finite‑state inver…
On fixed points and equalizers of injective endomorphisms of the free group at infinity
André Carvalho, Pedro V. Silva
We study equalizers and fixed points of monomorphisms of free groups at infinity. We show that the action of the equalizer of two monomorphisms on the regular points of the equaliz…
A language-theoretic approach to study the density of subsets in free groups
André Carvalho
In this paper, we study the density of subsets of nonabelian free groups using relative densities of languages. We start by proving some basic properties about the density of a lan…
Conjugacy languages and conjugacy growth relative to subsets of groups
André Carvalho, Ana-Catarina C. Monteiro
In this paper, we explore conjugacy languages when the base problem is the generalized conjugacy problem (with constraints): given and , does have a conjug…
On the dynamics of endomorphisms of the direct product of two free groups
André Carvalho
We prove that Brinkmann's problems are decidable for endomorphisms of : given and , it is decidable w…