YES(?,O(n^1)) Problem: -(-(neg(x),neg(x)),-(neg(y),neg(y))) -> -(-(x,y),-(x,y)) Proof: Bounds Processor: bound: 1 enrichment: match automaton: final states: {2,1} transitions: -1(1,2) -> 1* -1(2,1) -> 1* -1(1,1) -> 1* -1(2,2) -> 1* neg0(2) -> 2* neg0(1) -> 2* problem: Qed