MAYBE 0.08/0.17 MAYBE 0.08/0.17 0.08/0.17 Problem: 0.08/0.17 g(x,y) -> x 0.08/0.17 g(x,y) -> y 0.08/0.17 f(s(x),y,y) -> f(y,x,s(x)) 0.08/0.17 0.08/0.17 Proof: 0.08/0.17 Open 0.08/0.17 EOF