YES TRS: f(0()) -> 1() f(s(x)) -> g(x,s(x)) g(0(),y) -> y g(s(x),y) -> g(x,+(y,s(x))) +(x,0()) -> x +(x,s(y)) -> s(+(x,y)) g(s(x),y) -> g(x,s(+(y,x))) linear polynomial interpretations on N: f_A(x1) = x1 f#_A(x1) = x1 + 3 0_A = 1 0#_A = 6 1_A = 0 1#_A = 5 s_A(x1) = x1 s#_A(x1) = 0 g_A(x1,x2) = x2 g#_A(x1,x2) = x2 + 2 +_A(x1,x2) = x1 +#_A(x1,x2) = x1 + 1 precedence: 0 = + > 1 = s > f > g