% Test complex terms

% Facts
customer("Adrian").
discount(0.5).
cost(X,2000).
umsatz("Hammer",3000).
value(3000).

% Rules
discount(X,umsatz(Y,3000),0.5) :- 	cost(X,2000),
						customer(X),
						discount(0.5),
						value(3000).

% Goal
:- solve(discount("Adrian", umsatz("Hammer",3000),X)).