Tiling systems that recognize two-dimensional languages are intrinsically non-deterministic models. We introduce the notion of deterministic tiling system that generalizes deterministic automata for strings. The corresponding family of languages matches all the requirements of a robust deterministic class. Furthermore we show that, differently from the one-dimensional case, there exist many cla...

In Software Engineering, as in Computing Science, the topics that we teach to our students can be considered as falling into two broad categories: the deterministic, and the non-deterministic. Deterministic topics are those where a specific scenario or operation leads to outcomes that can be assessed in terms of true/false values, and so this classification encompasses large elements of compute...

Several non-deterministic extensions to the λ -calculus have been proposed, e.g. [6, 7, 10–12, 24]. In these approaches, the parallel composition (sometimes called the must-convergent parallel composition) is such that if r and s are two λ -terms, the term r+ s (also written r ‖ s) represents the computation that runs either r or s non-deterministically. It is common to consider in these approa...

During the analysis phase of the development of a software system, conceptual models are created to establish a description of the problem domain. In this paper we introduce concepts that allow us to introduce non-determinism in the specification of behaviour in conceptual models and we provide formal and declarative semantics for these constructs. We integrate non-determinism with the concept ...

This paper examines the problem of adding non-deterministic constructs to a declarative database language based on Horn Clause Logic. We revise a previously proposed approach, the choice construct introduced by Krishnamurthy and Naqvi, from the viewpoints of amenability to efficient implementation and expressive power. Thus, we define a construct called dynamic choice, which is consistent with ...

We present a natural semantics for the untyped lazy -calculus plus McCarthy's amb, a nondeterministic choice operator. The natural semantics includes rules for both convergent behaviour (de ned inductively) and divergent behaviour (de ned co-inductively). This semantics is equivalent to a small step reduction semantics that corresponds closely to our operational intuitions about McCarthy's amb....

We present an approach to the speci cation of required external non-determinism: the willingness of a component to respond to a number of external action requests, using a language, COMMUNITY, which provides both permission and willingness guards on actions. This enables a program-like declaration of required non-determinism, in contrast to the use of a branching-time temporal logic. We give a ...

A deep connection exists between the interleaving semantics of concurrent processes and increasingly labelled combinatorial structures. In this paper we further explore this connection by studying the rich combinatorics of partially increasing structures underlying the operator of non-deterministic choice. Following the symbolic method of analytic combinatorics, we study the size of the computa...

Abstract. Resolving non-deterministic choices of choreographies is a crucial task. We introduce a novel notion of realisability for choreographies –called whole-spectrum implementation– that rules out deterministic implementations of roles that, no matter which context they are placed in, will never follow one of the branches of a non-deterministic choice. We show that, under some conditions, i...

The principle of truth-functionality (or compositionality) is a basic principle in many-valued logic in general, and in classical logic in particular. According to this principle, the truth-value of a complex formula is uniquely determined by the truth-values of its subformulas. However, real-world information is inescapably incomplete, uncertain, vague, imprecise or inconsistent, and these phe...