Abstract. Turing machines exposed to a small stochastic noise are considered. An exact characterisation of their (≈ Π0 2 ) computational power (as noise level tends to 0) is obt...
Unambiguity in alternating Turing machines has received considerable attention in the context of analyzing globally-unique games by Aida et al. [ACRW04] and in the design of effic...
This paper shows that satisfiability for Propositional Dynamic Logic with Intersection is EXPSPACE-hard. The proof uses a reduction from the word problem for alternating, exponent...
We associate the iterated block product of a bimachine with a deterministic Turing machine. This allows us to introduce new algebraic notions to study the behavior of the Turing m...
The Busy Beaver is an interesting theoretical problem proposed by Rado in 1962. In this paper we propose an evolutionary approach to this problem. We will focus on the representati...
Penousal Machado, Francisco Baptista Pereira, Am&i...