YES Problem: a(b(a(a(x1)))) -> c(b(a(b(a(x1))))) a(c(b(x1))) -> a(a(b(c(b(a(x1)))))) Proof: String Reversal Processor: a(a(b(a(x1)))) -> a(b(a(b(c(x1))))) b(c(a(x1))) -> a(b(c(b(a(a(x1)))))) Bounds Processor: bound: 1 enrichment: match automaton: final states: {7,1} transitions: b0(3) -> 4* b0(11) -> 12* b0(9) -> 10* b0(5) -> 6* a1(15) -> 16* a1(17) -> 18* a1(26) -> 27* a1(25) -> 26* a1(30) -> 31* c0(2) -> 3* c0(10) -> 11* a0(4) -> 5* a0(6) -> 1* a0(12) -> 7* a0(2) -> 8* a0(8) -> 9* f30() -> 2* b1(16) -> 17* b1(27) -> 28* b1(29) -> 30* b1(14) -> 15* c1(28) -> 29* c1(13) -> 14* 7 -> 4* 12 -> 25* 4 -> 13* 1 -> 8,9 31 -> 15* 18 -> 9* problem: Qed