Problem: F(x,A(G(x))) -> G(F(x,x)) F(x,G(x)) -> G(F(x,x)) A(x) -> x H(x) -> H(B(H(x))) Proof: sorted: (order) 0:H(x) -> H(B(H(x))) 1:F(x,A(G(x))) -> G(F(x,x)) F(x,G(x)) -> G(F(x,x)) A(x) -> x ----- sorts [] sort attachment (non-strict) F : 1 x 1 -> 1 A : 1 -> 1 G : 1 -> 1 H : 0 -> 0 B : 0 -> 0 ----- 0:H(x) -> H(B(H(x))) Church Rosser Transformation Processor (critical pair closing system, Thm 2.11): critical peaks: joinable Qed 1:F(x,A(G(x))) -> G(F(x,x)) F(x,G(x)) -> G(F(x,x)) A(x) -> x Church Rosser Transformation Processor (ac): F(x,A(G(x))) -> G(F(x,x)) F(x,G(x)) -> G(F(x,x)) A(x) -> x AC critical peaks: joinable AC-KBO Processor: precedence: A > F > G weight function: w0 = 1 w(G) = 2 w(F) = w(A) = 0 problem: Qed