The emerging field of Nominal Computation Theory is concerned with the theory of Nominal Sets and its applications to Computer Science. We investigate here the impact of nominal sets on the definition of Cellular Automata and on their computational capabilities, with a special focus on the emergent behavioural properties of this new model and their significance in the context of computationorie...

This thesis studies two major extensions of nominal terms. In particular, we study an extension with λ-abstraction over nominal unknowns and atoms, and an extension with an arguably better theory of freshness and α-equivalence. Nominal terms possess two levels of variable: atoms a represent variable symbols, and unknowns X are ‘real’ variables. As a syntax, they are designed to facilitate metap...

FIROUGHOUT 1989, popular wisdom held that the U.S. monetary authority was faced with a daunting policy task: it should not permit too much money growth and cause prices to rise too rapidly, but it should not allow too little money growth and cause the economy to tip into recession as real output would fall. Sympathy for monetary policymakers, however, is not necessarily widespread among economi...

Nominal terms use a characteristic combination of features: Two levels of variable: atoms a and unknowns X. Freshness conditions a#X and permutations π. An abstraction [a]r with a distinctive α-equivalence based on freshness and permutation. The first statement above is rendered in nominal terms as the equality judgement b#X ` [a]X =α [b](b a) ·X. a and b denote atoms, which represent the ‘x’ a...

Nominal matching and unification underly the dynamics of nominal rewriting. Urban, Pitts and Gabbay gave a nominal unification algorithm which finds the most general solution to a nominal matching or unification problem, if one exists. Later the algorithm was extended by Fernández and Gabbay to deal with name generation and locality. In this paper we describe first a direct implementation of th...

The problem of "classification" is a general problem of life. That classification abilities are necessary for the survival of every organism is an important insight of biology. Human beings classify consciously, unconsciously, and even subconsciously in all situations. When we confront a scientific problem, we try to solve it by first classifying the various parts of the problem. Therefore, the...

This paper presents two approaches to Portuguese anaphor resolution, one based on a morpho-syntactic information and other on semantic features. We present a corpus based evaluation, focusing especially on anaphoric definite descriptions, which includes direct, indirect and associative anaphors.