Package code.subst

This package abstracts a substitution.

See:
Description

Class Summary

IdSubst	This class represents the identity substitution.
Subst	Abstract base class of all substitutions.
VarSubst	This class represents a non-identity substitution.

Package code.subst Description

This package abstracts a substitution.

A substitution is a mapping from variables to terms. A substitution is computed by narrowing steps of a computation. A substitution, or computed answer is printed at the end of a computation together with the computed value.

A substitution is computed and represented incrementally, a characteristic that influences the representation. The identity substitution is a singleton defined in the base class.