| m ≠ n0 + 1, lf(0) = nextl(0, a), m < n0, ∀ m. m < n0 → lf(m + 1) = nextl(m + 1, lf(m).last) ⊦ lf(m + 1) = nextl(m + 1, lf(m).last), m = n0, n0 = 0 |
lf(0) = nextl(0, a), m < n0, ∀ m. m < n0 → lf(m + 1) = nextl(m + 1, lf(m).last) ⊦ lf(m + 1) = nextl(m + 1, lf(m).last), m = n0, n0 = 0, m = n0 + 1