















4
%   Purpose: Implement finite maps.
%   Needs  : list_to_assoc from ASSOC.PL, ord_disjoint from ORDSET.PL

/*  A finite map is a function from terms to terms with a finite
    domain.  This definition actually implies that its domain
    consists of ground terms, and the code below assumes that.
    The representation is similar to the representation for bags
    (indeed a bag could be regarded as a map from keys to integers),
    that is










































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































