Report Number: CS-TR-75-507
Institution: Stanford University, Department of Computer Science
Title: Towards a semantic theory of dynamic binding.
Author: Gordon, Michael J. C.
Date: August 1975
Abstract: 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.