YES(?,O(n^1)) Problem: a(b(a(a(a(b(x1)))))) -> c(c(a(x1))) c(x1) -> b(a(a(a(b(x1))))) Proof: Bounds Processor: bound: 1 enrichment: match automaton: final states: {3,2} transitions: b1(4) -> 5* b1(8) -> 9* a1(5) -> 6* a1(7) -> 8* a1(6) -> 7* a0(1) -> 2* b0(1) -> 1* c0(1) -> 3* 1 -> 4* 9 -> 3* problem: Qed