⊦ Rton(n)(s, s0) ↔ (∀ m. m ≤ n → Ry(m)(s, s0))
Gr(n0 + 1)(s, s0) ⊦ ∀ m. m ≤ n0 → Ry(m)(s, s0)
Used terms: s0, s, n0