Input TRS:
    1: fst(0(),Z) -> nil()
    2: fst(s(X),cons(Y,Z)) -> cons(Y,n__fst(activate(X),activate(Z)))
    3: from(X) -> cons(X,n__from(s(X)))
    4: add(0(),X) -> X
    5: add(s(X),Y) -> s(n__add(activate(X),Y))
    6: len(nil()) -> 0()
    7: len(cons(X,Z)) -> s(n__len(activate(Z)))
    8: fst(X1,X2) -> n__fst(X1,X2)
    9: from(X) -> n__from(X)
    10: add(X1,X2) -> n__add(X1,X2)
    11: len(X) -> n__len(X)
    12: activate(n__fst(X1,X2)) -> fst(X1,X2)
    13: activate(n__from(X)) -> from(X)
    14: activate(n__add(X1,X2)) -> add(X1,X2)
    15: activate(n__len(X)) -> len(X)
    16: activate(X) -> X
Number of strict rules: 16
Direct Order(PosReal,>,Poly) ... removes: 4 15 8 1 3 16 5 10 7 14 12 11 9 13 6 2
     s(x1)	weight: 23613 + x1
activate(x1)	weight: 35421 + 2 * x1
n__from(x1)	weight: x1
   fst(x1,x2)	weight: (/ 23619 2) + 2 * x1 + 2 * x2
n__add(x1,x2)	weight: x1 + 2 * x2
     0()	weight: 0
  from(x1)	weight: (/ 70841 2) + 2 * x1
   nil()	weight: 0
n__len(x1)	weight: x1
n__fst(x1,x2)	weight: x1 + x2
  cons(x1,x2)	weight: 11807 + x1 + x2
   add(x1,x2)	weight: (/ 23617 2) + 2 * x1 + 2 * x2
   len(x1)	weight: (/ 70841 2) + 2 * x1
Number of strict rules: 0
YES