MAYBE 25.55/10.18 MAYBE 25.55/10.18 25.55/10.18 Problem: 25.55/10.18 f(x,f(y,a())) -> f(a(),f(f(f(x,a()),a()),y)) 25.55/10.18 25.55/10.18 Proof: 25.55/10.18 Open 25.55/10.19 EOF