%% Autor: %AUTHOR%
%% Datum: %DATE%
%%This Program Written By Mohsen Ashkboos.
%%How To Implement IF(expression)Then(Statments) Else(Statements)
%%If (X != Y) Sum=X+y; else Sum=X-y;
add(X,Y,Sum):- X=\=Y,!,Sum is X+Y;Sum is X-Y.
%%Find Max Number(Compare Two Numbers).
maxx(X,Y,Max):- X>=Y,!,Max is X;Max is Y.