YES

TRS:

  fst(0(),Z) -> nil()
  fst(s(X),cons(Y,Z)) -> cons(Y,n__fst(activate(X),activate(Z)))
  from(X) -> cons(X,n__from(n__s(X)))
  add(0(),X) -> X
  add(s(X),Y) -> s(n__add(activate(X),Y))
  len(nil()) -> 0()
  len(cons(X,Z)) -> s(n__len(activate(Z)))
  fst(X1,X2) -> n__fst(X1,X2)
  from(X) -> n__from(X)
  s(X) -> n__s(X)
  add(X1,X2) -> n__add(X1,X2)
  len(X) -> n__len(X)
  activate(n__fst(X1,X2)) -> fst(activate(X1),activate(X2))
  activate(n__from(X)) -> from(activate(X))
  activate(n__s(X)) -> s(X)
  activate(n__add(X1,X2)) -> add(activate(X1),activate(X2))
  activate(n__len(X)) -> len(activate(X))
  activate(X) -> X

linear polynomial interpretations on N:

  fst_A(x1,x2) = x1 + x2 + 3
  fst#_A(x1,x2) = x1 + x2 + 4
  0_A = 1
  0#_A = 1
  nil_A = 0
  nil#_A = 0
  s_A(x1) = x1
  s#_A(x1) = 1
  cons_A(x1,x2) = x2
  cons#_A(x1,x2) = 3
  n__fst_A(x1,x2) = x1 + x2 + 3
  n__fst#_A(x1,x2) = 1
  activate_A(x1) = x1
  activate#_A(x1) = x1 + 2
  from_A(x1) = x1 + 3
  from#_A(x1) = 4
  n__from_A(x1) = x1 + 3
  n__from#_A(x1) = 3
  n__s_A(x1) = x1
  n__s#_A(x1) = 0
  add_A(x1,x2) = x1 + x2 + 2
  add#_A(x1,x2) = x1 + x2 + 4
  n__add_A(x1,x2) = x1 + x2 + 2
  n__add#_A(x1,x2) = 3
  len_A(x1) = x1 + 2
  len#_A(x1) = x1 + 3
  n__len_A(x1) = x1 + 2
  n__len#_A(x1) = 1

precedence:

  0 = n__from = n__add > nil = activate > fst = from = add > cons = n__fst = n__s > n__len > len > s