domains
	list=integer*
	int=integer
predicates
	adder(list,int)
	add1(list,int,int)
clauses
	adder(T,S):-add1(T,0,S).
	add1([],S,S).
	add1([H|T],X,S):-A=X+H,add1(T,A,S).
goal
	write("Please input list:"),nl,
	write("X= "),readterm(list,X),
	adder(X,R),write("Result=",R).