| ∀ buf. 0 = datasize(buf, n) ↔ (∀ n0. n0 < n → buf[n0] = empty) ⊦ 0 = (buf[n] = empty ⊃ datasize(buf, n);n + 1) ↔ (∀ n0. ¬ n < n0 → buf[n0] = empty) |
0 = (buf[n] = empty ⊃ datasize(buf, n);n + 1), ∀ buf. 0 = datasize(buf, n) ↔ (∀ n0. n0 < n → buf[n0] = empty) ⊦ ∀ n0. ¬ n < n0 → buf[n0] = empty
∀ buf. 0 = datasize(buf, n) ↔ (∀ n0. n0 < n → buf[n0] = empty), ∀ n0. ¬ n < n0 → buf[n0] = empty ⊦ 0 = (buf[n] = empty ⊃ datasize(buf, n);n + 1)