| n0 + n < # buf, n0 + n ≤ # buf → (isempty(buf, n0, n) ↔ (∀ n2. n0 ≤ n2 ∧ n2 < n0 + n → buf[n2] = empty)) ⊦ buf[n0 + n] = empty ∧ isempty(buf, n0, n) ↔ (∀ n1. n0 ≤ n1 ∧ ¬ n0 + n < n1 → buf[n1] = empty) |
isempty(buf, n0, n) ↔ (∀ n2. n0 ≤ n2 ∧ n2 < n0 + n → buf[n2] = empty), n0 + n < # buf ⊦ buf[n0 + n] = empty ∧ isempty(buf, n0, n) ↔ (∀ n1. n0 ≤ n1 ∧ ¬ n0 + n < n1 → buf[n1] = empty)
Used simplifier rules: ⊦ m < n → m ≤ n; (s)