Increments each number - back to content

		?- inc(12,R).
		R=13
		?- mapcar(inc,[1,2,3],R).
		R=[2,3,4]
		


		inc(X,Y):- Y is X + 1.

		mapcar(F,[],[]).
		mapcar(F,[H|T],[R|RT]):- F(H,R),mapcar(F,T,RT).