YES TRS: +(x,0()) -> x +(0(),x) -> x +(s(x),s(y)) -> s(s(+(x,y))) +(+(x,y),z) -> +(x,+(y,z)) *(x,0()) -> 0() *(0(),x) -> 0() *(s(x),s(y)) -> s(+(*(x,y),+(x,y))) *(*(x,y),z) -> *(x,*(y,z)) sum(nil()) -> 0() sum(cons(x,l)) -> +(x,sum(l)) prod(nil()) -> s(0()) prod(cons(x,l)) -> *(x,prod(l)) max/plus interpretations on N: +_A(x1,x2) = max{9, 2 + x1, x2} +#_A(x1,x2) = max{0, 2, 13} 0_A = 10 0#_A = 1 s_A(x1) = max{10, -1} s#_A(x1) = max{5, -1} *_A(x1,x2) = max{10, 9, 9} *#_A(x1,x2) = max{13, 3, 4} sum_A(x1) = max{9, 3 + x1} sum#_A(x1) = max{14, 16} nil_A = 7 nil#_A = 6 cons_A(x1,x2) = max{5, -1 + x1, 5 + x2} cons#_A(x1,x2) = max{17, -1, 1 + x2} prod_A(x1) = max{10, 9} prod#_A(x1) = max{2, -2} precedence: nil > s = cons > prod > * = sum > + = 0