%   File   : pfcsyntax.pl
%   Author : Tim Finin, finin@prc.unisys.com
%   Purpose: syntactic sugar for Pfc - operator definitions and term expansions.

:- op(500,fx,'~').
:- op(1050,xfx,('=>')).
:- op(1050,xfx,'<=>').
:- op(1050,xfx,('<=')).
:- op(1100,fx,('=>')).
:- op(1150,xfx,('::::')).

:- multifile('term_expansion'/2).

term_expansion((P=>Q),(:- add((P=>Q)))).
%term_expansion((P=>Q),(:- add(('<='(Q,P))))).  % speed-up attempt
term_expansion(('<='(P,Q)),(:- add(('<='(P,Q))))).
term_expansion((P<=>Q),(:- add((P<=>Q)))).
term_expansion((RuleName :::: Rule),(:- add((RuleName :::: Rule)))).
term_expansion((=>P),(:- add(P))).