YES(?,O(n^1)) Problem: b(b(x1)) -> b(a(x1)) a(b(x1)) -> b(c(c(x1))) a(c(x1)) -> a(a(x1)) c(a(x1)) -> b(a(a(x1))) Proof: Bounds Processor: bound: 0 enrichment: match automaton: final states: {4,3,2} transitions: b0(1) -> 2* a0(1) -> 3* c0(1) -> 4* f60() -> 1* problem: Qed