| n < # buf0 + # buf1, ∀ n. n < # buf0 → buf0[n] = empty, ∀ n. n < # buf1 → buf1[n] = empty ⊦ (buf0 + buf1)[n] = empty |
⊦ n < # buf + # buf0 → (buf + buf0)[n] = (n < # buf ⊃ buf[n];buf0[n - # buf])
n < # buf0 + # buf1, ∀ n. n < # buf1 → buf1[n] = empty, ∀ n. n < # buf0 → buf0[n] = empty ⊦ (n < # buf0 ⊃ buf0[n];buf1[n - # buf0]) = empty
Used terms: n, buf1, buf0