:- module(external_operators,
	       [operators_for_external_representation/0,
		back_to_standard_representation_of_operators/0]).

operators_for_external_representation :-
	op(650, xfy, +),     % exclusive or
	op(650, xfy, <->),   % equivalence
	op(640, xfy, ->),    % implication
	op(630, xfy, v),     % disjunction
	op(620, xfy, ^),     % conjunction
	op(610, fy, ~),      % negation
	op(610, xfy, :),     % separates quantifier from following variable
	op(600, fx, exists), % there exists
	op(600, fx, forall). % for all

back_to_standard_representation_of_operators :-
	op(500, yfx, +),
	op(1050, xfy, ->),
	op(200, xfy, ^),
	op(900, fy, ~).