YES

TRS:

  U11(tt(),V2) -> U12(isNat(activate(V2)))
  U12(tt()) -> tt()
  U21(tt()) -> tt()
  U31(tt(),N) -> activate(N)
  U41(tt(),M,N) -> U42(isNat(activate(N)),activate(M),activate(N))
  U42(tt(),M,N) -> s(plus(activate(N),activate(M)))
  isNat(n__0()) -> tt()
  isNat(n__plus(V1,V2)) -> U11(isNat(activate(V1)),activate(V2))
  isNat(n__s(V1)) -> U21(isNat(activate(V1)))
  plus(N,0()) -> U31(isNat(N),N)
  plus(N,s(M)) -> U41(isNat(M),M,N)
  0() -> n__0()
  plus(X1,X2) -> n__plus(X1,X2)
  s(X) -> n__s(X)
  activate(n__0()) -> 0()
  activate(n__plus(X1,X2)) -> plus(activate(X1),activate(X2))
  activate(n__s(X)) -> s(activate(X))
  activate(X) -> X

linear polynomial interpretations on N:

  U11_A(x1,x2) = 1
  U11#_A(x1,x2) = x2 + 6
  tt_A = 1
  tt#_A = 1
  U12_A(x1) = 1
  U12#_A(x1) = 2
  isNat_A(x1) = 1
  isNat#_A(x1) = x1 + 2
  activate_A(x1) = x1
  activate#_A(x1) = x1 + 4
  U21_A(x1) = 1
  U21#_A(x1) = 2
  U31_A(x1,x2) = x2
  U31#_A(x1,x2) = x2 + 5
  U41_A(x1,x2,x3) = x2 + x3 + 8
  U41#_A(x1,x2,x3) = x2 + x3 + 8
  U42_A(x1,x2,x3) = x2 + x3 + 8
  U42#_A(x1,x2,x3) = x1 + x2 + x3 + 6
  s_A(x1) = x1 + 3
  s#_A(x1) = 4
  plus_A(x1,x2) = x1 + x2 + 5
  plus#_A(x1,x2) = x1 + x2 + 6
  n__0_A = 1
  n__0#_A = 0
  n__plus_A(x1,x2) = x1 + x2 + 5
  n__plus#_A(x1,x2) = x1 + 5
  n__s_A(x1) = x1 + 3
  n__s#_A(x1) = 3
  0_A = 1
  0#_A = 1

precedence:

  U41 > U42 = n__plus > U11 = U31 = s > U12 = activate > tt = plus = n__s > isNat = n__0 > U21 = 0