Concrete computability.

L1-Computability, Layerwise Computability and Solovay Reducibility

We propose a hierarchy of classes of functions that corresponds to the hierarchy of randomness notions. Each class of functions converges at the corresponding random points. We give various characterizations of the classes, that is, characterizations via integral tests, L-computability and layerwise computability. Furthermore, the relation among these classes is formulated using a version of So...

Computability versus exact computability of martingales

This note gives a simple example of a polynomial time computable martingale that has rational values but is not exactly computable.

Computability Theory

Computability Theory

formalisms of computability

Distributive Computability

This thesis presents a series of theoretical results and practical realisations about the theory of computation in distributive categories. Distributive categories have been proposed as a foundational tool for Computer Science in the last years, starting from the papers of R.F.C. Walters. We shall focus on two major topics: distributive computability, i.e., a generalized theory of computability...