4.1.5.4 Built-in Operators

     :- op( 1200, xfx, [ :-, --> ]).
     :- op( 1200,  fx, [ :-, ?- ]).
     :- op( 1150,  fx, [ mode, public, dynamic, volatile, discontiguous,
                         multifile, block, meta_predicate,
                         initialization ]).
     :- op( 1100, xfy, [ ;, do ]).
     :- op( 1050, xfy, [ -> ]).
     :- op( 1000, xfy, [ ',' ]).
     :- op(  900,  fy, [ \+, spy, nospy ]).
     :- op(  700, xfx, [ =, \=, is, =.., ==, \==, @<, @>, @=<, @>=,
                                     =:=, =\=, <, >, =<, >= ]).
     :- op(  550, xfy, [ : ]).
     :- op(  500, yfx, [ +, -, \, /\, \/ ]).
     :- op(  400, yfx, [ *, /, //, mod, rem, <<, >> ]).
     :- op(  200, xfx, [ ** ]).
     :- op(  200, xfy, [ ^ ]).
     :- op(  200,  fy, [ +, -, \ ]).

the above operators are as in the ISO Prolog standard, except the following, which are not present in ISO Prolog at all:

     :- op( 1150,  fx, [ mode, public, dynamic, volatile, discontiguous,
                         multifile, block, meta_predicate,
                         initialization ]).
     :- op( 1100, xfy, [ do ]).
     :- op(  900,  fy, [ spy, nospy ]).
     :- op(  550, xfy, [ : ]).
     :- op(  500, yfx, [ \ ]).
     :- op(  200,  fy, [ + ]).