| leninv(nσ) = ⌜n1⌝ + ⌜1⌝ , ⌜n⌝ < # nσ, n1 + 1 < nσ[n], stutf(nσ) ⊦ |
⊦ stutf(nσ) → (leninv(nσ) = ⌜n⌝ + ⌜1⌝ ↔ (# nσ = ∞ ⊃ ∃ m. nσ[m] = n ∧ (∀ m0. m < m0 → nσ[m0] = n + 1);nσ[(# nσ).n - 1] = n))
n1 + 1 < nσ[n], ⌜n⌝ < # nσ, stutf(nσ), (# nσ = ∞ ⊃ ∃ m. nσ[m] = n1 ∧ (∀ m0. m < m0 → nσ[m0] = n1 + 1);nσ[(# nσ).n - 1] = n1) ⊦
Used terms: n1, nσ