YES(?,O(n^1)) Problem: f(f(a(),x),y) -> h(h(f(f(x,f(a(),y)),a()))) Proof: Bounds Processor: bound: 0 enrichment: match automaton: final states: {3} transitions: f0(1,2) -> 3* f0(2,1) -> 3* f0(1,1) -> 3* f0(2,2) -> 3* a0() -> 1* h0(2) -> 2* h0(1) -> 2* problem: Qed