/* PROCEDURES THAT IMPLEMENT THE TESTING OF EXPRESSIONS */

/* a "check_gap" task is represented by the predicate
		check_gap(priority,expression)
 */



/* ACCESS TO PARTS */

priority( check_gap(Priority,_), Priority).



/* PERFORMING TASKS */

do( check_gap(Priority,Expr) ) :-
   writef('checking expression %t \n',[Expr]),
   !.


do( nothing ) :-
   writef('nothing to do\n',[]),
   !.
