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(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)
  add(X1,X2) -> n__add(X1,X2)
  len(X) -> n__len(X)
  activate(n__fst(X1,X2)) -> fst(X1,X2)
  activate(n__from(X)) -> from(X)
  activate(n__add(X1,X2)) -> add(X1,X2)
  activate(n__len(X)) -> len(X)
  activate(X) -> X

max/plus interpretations on N:

  fst_A(x1,x2) = max{47, 47 + x1, 31 + x2}
  fst#_A(x1,x2) = max{1, 3 + x1, 7 + x2}
  0_A = 47
  0#_A = 49
  nil_A = 48
  nil#_A = 48
  s_A(x1) = max{35, 32 + x1}
  s#_A(x1) = max{32, 43}
  cons_A(x1,x2) = max{31, 62, 32 + x2}
  cons#_A(x1,x2) = max{0, 0, 39}
  n__fst_A(x1,x2) = max{0, 15 + x1, -1 + x2}
  n__fst#_A(x1,x2) = max{2, 0, 0}
  activate_A(x1) = max{46, 32 + x1}
  activate#_A(x1) = max{42, 34 + x1}
  from_A(x1) = max{79, 46}
  from#_A(x1) = max{44, 46}
  n__from_A(x1) = max{47, 13}
  n__from#_A(x1) = max{46, 45}
  add_A(x1,x2) = max{48, 47 + x1, 93 + x2}
  add#_A(x1,x2) = max{45, 9 + x1, 45}
  n__add_A(x1,x2) = max{61, 15 + x1, 61 + x2}
  n__add#_A(x1,x2) = max{45, 8, 45}
  len_A(x1) = max{46, x1}
  len#_A(x1) = max{41, 2 + x1}
  n__len_A(x1) = max{0, -32 + x1}
  n__len#_A(x1) = max{40, -1}

precedence:

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