8.19/3.27 YES 8.19/3.27 8.19/3.27 Problem: 8.19/3.27 a(a(x)) -> a(b(a(x))) 8.19/3.27 b(a(b(x))) -> a(c(a(x))) 8.19/3.27 8.19/3.27 Proof: 8.19/3.27 AT confluence processor 8.19/3.27 Complete TRS T' of input TRS: 8.19/3.27 a(a(x)) -> a(b(a(x))) 8.19/3.27 b(a(b(x))) -> a(c(a(x))) 8.19/3.27 8.19/3.27 T' = (P union S) with 8.19/3.27 8.19/3.27 TRS P: 8.19/3.27 8.19/3.27 TRS S:a(a(x)) -> a(b(a(x))) 8.19/3.27 b(a(b(x))) -> a(c(a(x))) 8.19/3.27 8.19/3.27 S is left-linear and P is reversible. 8.19/3.27 8.19/3.27 CP(S,S) = 8.19/3.27 a(a(b(a(x23)))) = a(b(a(a(x23)))), b(a(a(c(a(x24))))) = a(c(a(a(b(x24))))) 8.19/3.27 8.19/3.27 CP(S,P union P^-1) = 8.19/3.27 8.19/3.27 8.19/3.27 PCP_in(P union P^-1,S) = 8.19/3.27 8.19/3.27 8.19/3.27 We have to check termination of S: 8.19/3.27 8.19/3.27 Matrix Interpretation Processor: dim=3 8.19/3.27 8.19/3.27 interpretation: 8.19/3.27 [1 0 1] [0] 8.19/3.27 [b](x0) = [0 0 0]x0 + [1] 8.19/3.27 [0 0 0] [0], 8.19/3.27 8.19/3.27 [1 0 1] [0] 8.19/3.27 [a](x0) = [0 0 0]x0 + [1] 8.19/3.27 [0 1 0] [0], 8.19/3.27 8.19/3.27 [1 0 0] 8.19/3.27 [c](x0) = [0 0 0]x0 8.19/3.27 [0 0 0] 8.19/3.27 orientation: 8.19/3.27 [1 1 1] [0] [1 1 1] [0] 8.19/3.27 a(a(x)) = [0 0 0]x + [1] >= [0 0 0]x + [1] = a(b(a(x))) 8.19/3.27 [0 0 0] [1] [0 0 0] [1] 8.19/3.27 8.19/3.27 [1 0 1] [1] [1 0 1] [0] 8.19/3.27 b(a(b(x))) = [0 0 0]x + [1] >= [0 0 0]x + [1] = a(c(a(x))) 8.19/3.27 [0 0 0] [0] [0 0 0] [0] 8.19/3.27 problem: 8.19/3.27 a(a(x)) -> a(b(a(x))) 8.19/3.27 Matrix Interpretation Processor: dim=2 8.19/3.27 8.19/3.27 interpretation: 8.19/3.27 [2 0] [2] 8.19/3.27 [b](x0) = [0 0]x0 + [0], 8.19/3.27 8.19/3.27 [1 1] [0] 8.19/3.27 [a](x0) = [1 1]x0 + [3] 8.19/3.27 orientation: 8.19/3.27 [2 2] [3] [2 2] [2] 8.19/3.27 a(a(x)) = [2 2]x + [6] >= [2 2]x + [5] = a(b(a(x))) 8.19/3.27 problem: 8.19/3.27 8.19/3.27 Qed 8.19/3.27 EOF