YES(?,O(n^2)) Problem: f(x,a()) -> x f(x,g(y)) -> f(g(x),y) Proof: Complexity Transformation Processor: strict: f(x,a()) -> x f(x,g(y)) -> f(g(x),y) weak: Matrix Interpretation Processor: dimension: 1 max_matrix: 1 interpretation: [g](x0) = x0, [f](x0, x1) = x0 + x1, [a] = 1 orientation: f(x,a()) = x + 1 >= x = x f(x,g(y)) = x + y >= x + y = f(g(x),y) problem: strict: f(x,g(y)) -> f(g(x),y) weak: f(x,a()) -> x Matrix Interpretation Processor: dimension: 2 max_matrix: [1 1] [0 1] interpretation: [0] [g](x0) = x0 + [1], [1 1] [0] [f](x0, x1) = x0 + [0 1]x1 + [1], [0] [a] = [0] orientation: [1 1] [1] [1 1] [0] f(x,g(y)) = x + [0 1]y + [2] >= x + [0 1]y + [2] = f(g(x),y) [0] f(x,a()) = x + [1] >= x = x problem: strict: weak: f(x,g(y)) -> f(g(x),y) f(x,a()) -> x Qed