MAYBE 150.72/55.37 MAYBE 150.72/55.37 150.72/55.37 Problem: 150.72/55.37 a(a(a(b(x1)))) -> b(b(x1)) 150.72/55.37 b(b(x1)) -> a(b(a(a(x1)))) 150.72/55.37 150.72/55.37 Proof: 150.72/55.37 Open 150.72/55.37 EOF