YES Problem: f(empty(),l) -> l f(cons(x,k),l) -> g(k,l,cons(x,k)) g(a,b,c) -> f(a,cons(b,c)) Proof: Matrix Interpretation Processor: dim=1 interpretation: [f](x0, x1) = 6x0 + x1 + 1, [g](x0, x1, x2) = 7x0 + x1 + 2x2 + 2, [empty] = 0, [cons](x0, x1) = x0 + 2x1 + 1 orientation: f(empty(),l) = l + 1 >= l = l f(cons(x,k),l) = 12k + l + 6x + 7 >= 11k + l + 2x + 4 = g(k,l,cons(x,k)) g(a,b,c) = 7a + b + 2c + 2 >= 6a + b + 2c + 2 = f(a,cons(b,c)) problem: g(a,b,c) -> f(a,cons(b,c)) Matrix Interpretation Processor: dim=3 interpretation: [1 0 0] [1 0 0] [f](x0, x1) = [0 0 0]x0 + [0 0 1]x1 [0 0 0] [0 0 0] , [1 0 0] [1 0 0] [1 0 0] [1] [g](x0, x1, x2) = [0 0 0]x0 + [0 0 0]x1 + [1 0 0]x2 + [0] [0 0 0] [0 0 0] [0 0 0] [0], [1 0 0] [1 0 0] [cons](x0, x1) = [0 0 0]x0 + [0 0 0]x1 [0 0 0] [1 0 0] orientation: [1 0 0] [1 0 0] [1 0 0] [1] [1 0 0] [1 0 0] [1 0 0] g(a,b,c) = [0 0 0]a + [0 0 0]b + [1 0 0]c + [0] >= [0 0 0]a + [0 0 0]b + [1 0 0]c = f(a,cons(b,c)) [0 0 0] [0 0 0] [0 0 0] [0] [0 0 0] [0 0 0] [0 0 0] problem: Qed