YES(?,O(n^3)) Problem: f(f(a(),f(a(),a())),x) -> f(x,f(f(a(),a()),a())) Proof: Complexity Transformation Processor: strict: f(f(a(),f(a(),a())),x) -> f(x,f(f(a(),a()),a())) weak: Matrix Interpretation Processor: dimension: 3 max_matrix: [1 1 0] [0 0 1] [0 0 0] interpretation: [1 0 0] [1 1 0] [0] [f](x0, x1) = [0 0 1]x0 + [0 0 1]x1 + [1] [0 0 0] [0 0 0] [0], [0] [a] = [0] [1] orientation: [1 1 0] [3] [1 0 0] [2] f(f(a(),f(a(),a())),x) = [0 0 1]x + [1] >= [0 0 1]x + [1] = f(x,f(f(a(),a()),a())) [0 0 0] [0] [0 0 0] [0] problem: strict: weak: f(f(a(),f(a(),a())),x) -> f(x,f(f(a(),a()),a())) Qed