Towards a Semantic Theory of Dynamic Binding,

摘要

The results in this paper contribute to the formulation of a semantic theory of dynamic binding (fluid variables). The axioms and theorems are language independent in that they don't talk about programs - i.e. syntactic objects - but just about elements in certain domains. Firstly the equivalence (in the circumstances where it's true) of 'tying a knot' through the environment (elaborated in the paper) and taking a least fixed point is shown. This is central in proving the correctness of LISP eval type interpreters. Secondly the relation which must hold between two environments if a program is to have the same meaning in both is established. It is shown how the theory can be applied to LISP to yield previously known facts. (Author)