NO Problem: a(b(x)) -> b(c(x)) a(c(x)) -> c(a(x)) b(b(x)) -> a(c(x)) c(b(x)) -> b(c(x)) c(b(x)) -> c(c(x)) c(c(x)) -> c(b(x)) 0(1(2(x))) -> 2(0(1(x))) 2(2(2(2(2(2(2(1(1(1(1(2(x)))))))))))) -> 2(1(2(2(0(1(2(1(1(0(1(0(x)))))))))))) Proof: sorted: (order-sorted) 0:0(1(2(x))) -> 2(0(1(x))) 2(2(2(2(2(2(2(1(1(1(1(2(x)))))))))))) -> 2(1(2(2(0(1(2(1(1(0(1(0(x)))))))))))) 1:a(b(x)) -> b(c(x)) a(c(x)) -> c(a(x)) b(b(x)) -> a(c(x)) c(b(x)) -> b(c(x)) c(b(x)) -> c(c(x)) c(c(x)) -> c(b(x)) ----- sorts [] sort attachment (non-strict) a : 1 -> 1 b : 1 -> 1 c : 1 -> 1 0 : 0 -> 0 1 : 0 -> 0 2 : 0 -> 0 ----- 0:0(1(2(x))) -> 2(0(1(x))) 2(2(2(2(2(2(2(1(1(1(1(2(x)))))))))))) -> 2(1(2(2(0(1(2(1(1(0(1(0(x)))))))))))) Nonconfluence Processor: terms: 2(0(1(1(2(2(2(0(1(1(1(0(1(0(x270)))))))))))))) *<- 0(1(2(2 ( 2 ( 2(2(2(2(1(1(1(1(2(x270)))))))))))))) ->* 2(2(2(2(2(2(2(0(1(1(1(1(1(2(x270)))))))))))))) Qed 1:a(b(x)) -> b(c(x)) a(c(x)) -> c(a(x)) b(b(x)) -> a(c(x)) c(b(x)) -> b(c(x)) c(b(x)) -> c(c(x)) c(c(x)) -> c(b(x)) Open