| lfgen(0)(0) = a ', n1 ≤ n0, lfgen(n0)(0) = a ' ∧ (∀ m. m < n0 → lfgen(n0)(m + 1) = nextl(m, lfgen(n0)(m).last) ∧ lfgen(n0)(m) ≠ []), ∀ n. lfgen(n)(0) = a ' ∧ (∀ m. m < n → lfgen(n)(m + 1) = nextl(m, lfgen(n)(m).last) ∧ lfgen(n)(m) ≠ []), ∀ n, a. nextl(n, a) ≠ [] ⊦ lfgen(n1)(0) = lfgen(n0)(0) |
lfgen(0)(0) = a ', lfgen(n0)(0) = a ', n1 ≤ n0, ∀ m. m < n0 → lfgen(n0)(m + 1) = nextl(m, lfgen(n0)(m).last) ∧ lfgen(n0)(m) ≠ [], ∀ n. lfgen(n)(0) = a ' ∧ (∀ m. m < n → lfgen(n)(m + 1) = nextl(m, lfgen(n)(m).last) ∧ lfgen(n)(m) ≠ []), ∀ n, a. nextl(n, a) ≠ [] ⊦ lfgen(n1)(0) = a '