YES Problem: top(sent(x)) -> top(check(rest(x))) rest(nil()) -> sent(nil()) rest(cons(x,y)) -> sent(y) check(sent(x)) -> sent(check(x)) check(rest(x)) -> rest(check(x)) check(cons(x,y)) -> cons(check(x),y) check(cons(x,y)) -> cons(x,check(y)) check(cons(x,y)) -> cons(x,y) Proof: Matrix Interpretation Processor: dim=1 interpretation: [cons](x0, x1) = x0 + 2x1 + 7, [nil] = 0, [check](x0) = x0, [rest](x0) = 2x0, [top](x0) = 4x0 + 1, [sent](x0) = 3x0 orientation: top(sent(x)) = 12x + 1 >= 8x + 1 = top(check(rest(x))) rest(nil()) = 0 >= 0 = sent(nil()) rest(cons(x,y)) = 2x + 4y + 14 >= 3y = sent(y) check(sent(x)) = 3x >= 3x = sent(check(x)) check(rest(x)) = 2x >= 2x = rest(check(x)) check(cons(x,y)) = x + 2y + 7 >= x + 2y + 7 = cons(check(x),y) check(cons(x,y)) = x + 2y + 7 >= x + 2y + 7 = cons(x,check(y)) check(cons(x,y)) = x + 2y + 7 >= x + 2y + 7 = cons(x,y) problem: top(sent(x)) -> top(check(rest(x))) rest(nil()) -> sent(nil()) check(sent(x)) -> sent(check(x)) check(rest(x)) -> rest(check(x)) check(cons(x,y)) -> cons(check(x),y) check(cons(x,y)) -> cons(x,check(y)) check(cons(x,y)) -> cons(x,y) Matrix Interpretation Processor: dim=1 interpretation: [cons](x0, x1) = 3x0 + 2x1 + 4, [nil] = 0, [check](x0) = 3x0, [rest](x0) = 2x0, [top](x0) = 4x0, [sent](x0) = 6x0 orientation: top(sent(x)) = 24x >= 24x = top(check(rest(x))) rest(nil()) = 0 >= 0 = sent(nil()) check(sent(x)) = 18x >= 18x = sent(check(x)) check(rest(x)) = 6x >= 6x = rest(check(x)) check(cons(x,y)) = 9x + 6y + 12 >= 9x + 2y + 4 = cons(check(x),y) check(cons(x,y)) = 9x + 6y + 12 >= 3x + 6y + 4 = cons(x,check(y)) check(cons(x,y)) = 9x + 6y + 12 >= 3x + 2y + 4 = cons(x,y) problem: top(sent(x)) -> top(check(rest(x))) rest(nil()) -> sent(nil()) check(sent(x)) -> sent(check(x)) check(rest(x)) -> rest(check(x)) Matrix Interpretation Processor: dim=3 interpretation: [0] [nil] = [0] [1], [1 1 0] [check](x0) = [0 0 0]x0 [0 0 0] , [1 0 1] [rest](x0) = [0 1 0]x0 [0 0 1] , [1 0 1] [1] [top](x0) = [1 0 1]x0 + [1] [1 0 1] [0], [1 0 0] [sent](x0) = [0 1 0]x0 [0 1 1] orientation: [1 1 1] [1] [1 1 1] [1] top(sent(x)) = [1 1 1]x + [1] >= [1 1 1]x + [1] = top(check(rest(x))) [1 1 1] [0] [1 1 1] [0] [1] [0] rest(nil()) = [0] >= [0] = sent(nil()) [1] [1] [1 1 0] [1 1 0] check(sent(x)) = [0 0 0]x >= [0 0 0]x = sent(check(x)) [0 0 0] [0 0 0] [1 1 1] [1 1 0] check(rest(x)) = [0 0 0]x >= [0 0 0]x = rest(check(x)) [0 0 0] [0 0 0] problem: top(sent(x)) -> top(check(rest(x))) check(sent(x)) -> sent(check(x)) check(rest(x)) -> rest(check(x)) Matrix Interpretation Processor: dim=1 interpretation: [check](x0) = 4x0, [rest](x0) = x0 + 1, [top](x0) = x0, [sent](x0) = 5x0 + 6 orientation: top(sent(x)) = 5x + 6 >= 4x + 4 = top(check(rest(x))) check(sent(x)) = 20x + 24 >= 20x + 6 = sent(check(x)) check(rest(x)) = 4x + 4 >= 4x + 1 = rest(check(x)) problem: Qed