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.
Logical positivism priori", statements claiming states of facts but known true before experience—by arriving at transcendental idealism, attributing the mind a constructive role in phenomena by arranging sense data into the very experience "space", "time", and "substance". Thus, Kant saved Newton's law of universal gravitation from Hume's problem of induction by finding uniformity of nature to be "a priori" knowledge. Logical positivists rejected Kant's synthethic "a priori", and staked Hume's fork, whereby a statement is either analytic and "a priori" (thus necessary and verifiable logically) or synthetic and "a posteriori" (thus contingent and verifiable empirically). Early, most logical positivists proposed that all