op/3
op(Precedence, Associativity, Operator) Declares operators.
op(Precedence, Associativity, Operator)
Declares operators.
op(+integer, +associativity, +atom_or_atom_list)
:- op(950, fx, +). :- op(950, fx, ?). :- op(950, fx, @). :- op(950, fx, -).