MAYBE 28.19/10.18 MAYBE 28.19/10.18 28.19/10.18 Problem: 28.19/10.18 f(y,f(x,f(a(),x))) -> f(f(a(),f(x,a())),f(a(),y)) 28.19/10.18 f(x,f(x,y)) -> f(f(f(x,a()),a()),a()) 28.19/10.18 28.19/10.18 Proof: 28.19/10.18 Open 28.19/10.19 EOF