If the advancement of the general art of programming requires the continuing invention and elaboration of paradigms, advancement of the art of the in… - Robert W. Floyd

A semantic definition of a particular set of command types, then, is a rule for constructing, for any command of one of these types, a verification condition on the antecedents and consequents.

It is, therefore, possible to extend a partially specified interpretation to a complete interpretation, without loss of verifiability, [...] This fact offers the possibility of automatic verification of programs, the programmer merely tagging entrances and one edge in each innermost loop.

If there is ever a science of programming language design, it will probably consist largely of matching languages to the design methods they support.