YES(?,O(n^1)) Problem: +(*(x,y),*(x,z)) -> *(x,+(y,z)) +(+(x,y),z) -> +(x,+(y,z)) +(*(x,y),+(*(x,z),u())) -> +(*(x,+(y,z)),u()) Proof: Bounds Processor: bound: 1 enrichment: match automaton: final states: {3} transitions: +0(1,2) -> 3* +0(2,1) -> 3* +0(1,1) -> 3* +0(2,2) -> 3* *0(1,2) -> 1* *0(2,1) -> 1* *0(1,1) -> 1* *0(2,2) -> 1* u0() -> 2* *1(2,3) -> 3* *1(1,3) -> 3* +1(1,2) -> 3* +1(2,1) -> 3* +1(1,1) -> 3* +1(2,2) -> 3* problem: Qed