| n + m ≤ # ar ⊦ ar1 = subarray(ar, n, m) ↔ (∃ ar0, ar2. ar = ar0 + ar1 + ar2 ∧ # ar0 = n ∧ # ar1 = m) |
ar1 = subarray(ar, n, m), n + m ≤ # ar ⊦ ∃ ar0, ar2. ar = ar0 + ar1 + ar2 ∧ # ar0 = n ∧ # ar1 = m
n + m ≤ # ar, ∃ ar0, ar2. ar = ar0 + ar1 + ar2 ∧ # ar0 = n ∧ # ar1 = m ⊦ ar1 = subarray(ar, n, m)