YES(?,O(n^2)) Problem: f(x,a()) -> x f(x,g(y)) -> f(g(x),y) Proof: RT Transformation Processor: strict: f(x,a()) -> x f(x,g(y)) -> f(g(x),y) weak: Bounds Processor: bound: 0 enrichment: match-rt automaton: final states: {4,5} transitions: f0(4,4) -> 4* f0(5,5) -> 4* f0(4,5) -> 4* f0(5,4) -> 4* a0() -> 5* g0(5) -> 4* g0(4) -> 4* 5 -> 4* problem: strict: f(x,g(y)) -> f(g(x),y) weak: f(x,a()) -> x Matrix Interpretation Processor: dimension: 2 interpretation: [5] [g](x0) = x0 + [3], [1 1] [1 8] [0 ] [f](x0, x1) = [0 1]x0 + [0 1]x1 + [12], [0] [a] = [0] orientation: [1 1] [1 8] [29] [1 1] [1 8] [8 ] f(x,g(y)) = [0 1]x + [0 1]y + [15] >= [0 1]x + [0 1]y + [15] = f(g(x),y) [1 1] [0 ] f(x,a()) = [0 1]x + [12] >= x = x problem: strict: weak: f(x,g(y)) -> f(g(x),y) f(x,a()) -> x Qed