YES Problem: a(b(x1)) -> b(a(a(x1))) b(c(x1)) -> c(b(x1)) a(a(x1)) -> a(c(a(x1))) Proof: String Reversal Processor: b(a(x1)) -> a(a(b(x1))) c(b(x1)) -> b(c(x1)) a(a(x1)) -> a(c(a(x1))) Bounds Processor: bound: 2 enrichment: match automaton: final states: {7,5,1} transitions: f30() -> 2* a0(2) -> 8* a0(9) -> 7* a0(4) -> 1* a0(3) -> 4* b0(2) -> 3* b0(6) -> 5* c0(2) -> 6* c0(8) -> 9* a1(14) -> 15* a1(26) -> 27* a1(16) -> 17* c1(15) -> 16* a2(22) -> 23* a2(24) -> 25* a2(31) -> 32* c2(30) -> 31* c2(23) -> 24* 1 -> 3,14 3 -> 14* 4 -> 26* 5 -> 6* 7 -> 8* 16 -> 22* 17 -> 27,1 25 -> 30,4,15 27 -> 23* 32 -> 27* problem: Qed