MAYBE 31.21/10.18 MAYBE 31.21/10.18 31.21/10.18 Problem: 31.21/10.18 a(x1) -> x1 31.21/10.18 a(a(x1)) -> b(x1) 31.21/10.18 b(x1) -> a(x1) 31.21/10.18 b(c(x1)) -> c(c(b(a(x1)))) 31.21/10.18 31.21/10.18 Proof: 31.21/10.18 Open 31.21/10.18 EOF