00001 :- foreign_pred paddints(+a, +b, -retval) from 00002 add_integers(a:int,b:int):int. 00003 :- foreign_pred paddfloats(+a,+b,-retval) from 00004 add_floats(a:float, b:float):float. 00005 :- foreign_pred pswapints(+a,+b,-a,-b) from 00006 swap_ints(a:intptr, b:intptr):void. 00007 :- foreign_pred psort(+a,-a) from 00008 sort(a:string(80)):void. 00009 :- foreign_pred plcsort(+a,-a) from 00010 sort(a:chars(80)):void. 00011