2732	 Guarded Commands Nondeterminacy and Formal Derivation of Programs	 So-called guarded commands are introduced as a building block for alternative and repetitive constructs that allow nondeterministic program components for which at least the activity evoked but possible even the final state is not necessarily uniquely determined by the initial state. For the formal derivation of programs expressed in terms of these constructs a calculus will be shown. programming languages sequencing primitives program semantics programming language semantics nondeterminacy case-construction repetition termination correctness proof derivation of programs programming methodology
