Sémantique dénotationnelleEn informatique, la sémantique dénotationnelle est une des approches permettant de formaliser la signification d'un programme en utilisant les mathématiques. Parmi les autres approches, on trouve la sémantique axiomatique et la sémantique opérationnelle. Cette discipline a été introduite par Christopher Strachey et Dana Scott. En général, la sémantique dénotationnelle utilise des techniques de programmation fonctionnelle pour décrire les langages informatiques, les architectures et les programmes.
History monoidIn mathematics and computer science, a history monoid is a way of representing the histories of concurrently running computer processes as a collection of strings, each string representing the individual history of a process. The history monoid provides a set of synchronization primitives (such as locks, mutexes or thread joins) for providing rendezvous points between a set of independently executing processes or threads.
Indeterminacy in concurrent computationIndeterminacy in concurrent computation is concerned with the effects of indeterminacy in concurrent computation. Computation is an area in which indeterminacy is becoming increasingly important because of the massive increase in concurrency due to networking and the advent of many-core computer architectures. These computer systems make use of arbiters which gives rise to indeterminacy. Patrick Hayes [1973] argued that the "usual sharp distinction that is made between the processes of computation and deduction, is misleading".
Trace theoryIn mathematics and computer science, trace theory aims to provide a concrete mathematical underpinning for the study of concurrent computation and process calculi. The underpinning is provided by an algebraic definition of the free partially commutative monoid or trace monoid, or equivalently, the history monoid, which provides a concrete algebraic foundation, analogous to the way that the free monoid provides the underpinning for formal languages.
Problème de l'arrêtvignette|L'animation illustre une machine impossible : il n'y a pas de machine qui lit n'importe quel code source d'un programme et dit si son exécution termine ou non. En théorie de la calculabilité, le problème de l'arrêt est le problème de décision qui détermine, à partir d'une description d'un programme informatique, et d'une entrée, si le programme s'arrête avec cette entrée ou non.
ComputationA computation is any type of arithmetic or non-arithmetic calculation that is well-defined. Common examples of computations are mathematical equations and computer algorithms. Mechanical or electronic devices (or, historically, people) that perform computations are known as computers. The study of computation is the field of computability, itself a sub-field of computer science. The notion that mathematical statements should be ‘well-defined’ had been argued by mathematicians since at least the 1600s, but agreement on a suitable definition proved elusive.
