Term Rewriting System R: [x] a(b(x)) -> b(b(a(a(x)))) Termination of R to be shown. This program has no overlaps, so it is sufficient to show innermost termination. R contains the following Dependency Pairs: A(b(x)) -> A(a(x)) A(b(x)) -> A(x) Furthermore, R contains one SCC. SCC1: A(b(x)) -> A(x) A(b(x)) -> A(a(x)) Found an infinite P-chain over R: P = A(b(x)) -> A(x) A(b(x)) -> A(a(x)) R = [a(b(x)) -> b(b(a(a(x))))] s = A(b(b(x''))) evaluates to t = A(b(b(a(a(x''))))) Thus, s starts an infinite reduction as s matches t. Non-Termination of R could be shown. Duration: 0.702 seconds.