instance, try clicking on the "Reduce" button:

let true = (\x (\y x)) in let false = (\x (\y y)) in let and = (\l (\r ((l r) false))) in ( ((((and false) false) yes) no) ((((and false) true) yes) no) ((((and true) false) yes) no) ((((and true) true) yes) no) )

You should see the