Logic programming that computational steps cannot be logically deduced. However, in concurrent logic programming, any result of a terminating computation is a logical consequence of the program, and any partial result of a partial computation is a logical consequence of the program and the residual goal (process network). Consequently, the indeterminacy of computations implies that not all logical consequences of the program can be deduced. Concurrent constraint logic programming combines concurrent logic programming and constraint logic programming, using constraints to control concurrency. A clause can contain a guard, which is a set of constraints that may block the applicability of the clause.
Analytic philosophy sought to understand language (and hence philosophical problems) by using formal logic to formalize the way in which philosophical statements are made. Wittgenstein developed a comprehensive system of logical atomism in his "Tractatus Logico-Philosophicus" (, 1921). He thereby argued that the universe is the totality of actual states of affairs and that these states of affairs can be expressed by the language of first-order predicate logic. Thus a "picture" of the universe can be construed by means of expressing atomic facts in the form of atomic propositions, and linking them using logical operators. During the late 1920s, to 1940s, a