Catálogo de publicaciones - libros

Two main mechanisms behind the functioning of biochemical reactions are facilitation and inhibition; these mechanisms are also central for the interaction between biochemical reactions. This observation underlies the theory of reaction systems which is a formal framework for the investigation of biochemical reactions, and especially interactions between them.

We add some new insights, and thus hopefully contribute to give new impetus, to an old theme: constructive mathematics, and topology in particular, can be thought of as an abstract way to deal with computation.

If a continuous function on a complete metric space has approximate roots and in a uniform manner at most one root, then it actually has a root. We validate this heuristic principle in Bishop–style constructive mathematics without countable choice, following Richman’s way of defining the completion of a metric space as the set of all locations.

Primary 03F60; Secondary 03E25, 26E40, 54E50.

We show that many so called discrete weak semilattices considered earlier in a series of author’s publications have hereditary undecidable first-order theories. Since such structures appear naturally in some parts of computability theory, we obtain several new undecidability results. This applies e.g. to the structures of complete numberings, of -degrees of index sets and of the Wadge degrees of partitions in the Baire space and -algebraic domains.

P Systems with proteins on membranes were introduced recently by A.Paun and B. Popa, in an effort to bridge the gap between membrane computing and brane calculi. In this variant, one considers multisets of objects inside the membranes as well as proteins on the membranes. The action of the proteins on the objects is classified broadly into 5 categories. In this paper, we study the computational power of these actions and come up with upper and lower bounds in terms of computational power for some of them.

The conventional wisdom presented in most computability books and historical papers is that there were several researchers in the early 1930’s working on various precise definitions and demonstrations of a function specified by a finite procedure and that they should all share approximately equal credit. This is incorrect. It was Turing who achieved the characterization, in the opinion of Gödel. We also explore Turing’s oracle machine and its analogous properties in analysis.

A jump inversion theorem for the degree spectra is presented. For a structure which degree spectrum is a subset of the jump spectrum of a structure , a structure is constructed as a Marker’s extension of such that the jump spectrum of is exactly the degree spectrum of and the degree spectrum of is a subset of the degree spectrum of .

In this paper we prove that every nonzero -degree is cuppable to ′ by a 1-generic -degree (so low and nontotal) and that every nonzero -c.e. e-degree is cuppable to ′ by an incomplete 3-c.e. -degree.

It would be a mistake to seek for a lesson that the advent of quantum computing has provided: the theory is rich in both physics and computer science terms. But my quarry is , or perhaps , central point that we should draw; and it concerns putative shifts in our understanding of the Church- Turing hypothesis inspired by reflection on quantum computation.

We propose a tentative parallel between computational features and cellular operations in order to explore the possibility that the cell itself is intrinsically and not metaphorically a symbol-processing, computing entity. Central to this possible identification is the notion of virtuality, as understood in computational theory.