| f(S0)(x), S0 ⊆ S, chain(λ n. (n = 0 ⊃ S0;S)) → (∀ x. f(λ x0. ∃ n. (n = 0 ⊃ S0;S)(x0))(x) ↔ (∃ n. f((n = 0 ⊃ S0;S))(x))) ⊦ f(S)(x) |
f(S0)(x), S0 ⊆ S ⊦ chain(λ n. (n = 0 ⊃ S0;S)), f(S)(x)
∀ x. f(λ x0. ∃ n. (n = 0 ⊃ S0;S)(x0))(x) ↔ (∃ n. f((n = 0 ⊃ S0;S))(x)), f(S0)(x), S0 ⊆ S ⊦ f(S)(x)