| kar[m1] = key-index(key0, n0), kar[m0] = key-index(key1, n1), m1 < n, m0 < n, m1 < # kar, m0 < # kar, n ≤ # kar, ∀ m. m < n → kar[m].idx < # ar ∧ ar[kar[m].idx].idx = m ⊦ valid-idx(kar[m0, key-index(key0, n0)][m1, key-index(key1, n1)], ar[n0, ar[n0].idx:= m0][n1, ar[n0, ar0[n0].idx:= m0][n1].idx:= m1], n) |
⊦ valid-idx(kar, ar, n) ↔ n ≤ # kar ∧ (∀ m. m < n → kar[m].idx < # ar ∧ ar[kar[m].idx].idx = m)
kar[m0] = key-index(key1, n1), kar[m1] = key-index(key0, n0), m0 < # kar, m1 < # kar, m0 < n, m1 < n, n ≤ # kar, ∀ m. m < n → kar[m].idx < # ar ∧ ar[kar[m].idx].idx = m ⊦ n ≤ # kar[m0, key-index(key0, n0)][m1, key-index(key1, n1)] ∧ (∀ m. m < n → kar[m0, key-index(key0, n0)][m1, key-index(key1, n1)][m].idx < # ar[n0, ar[n0].idx:= m0][n1, ar[n0, ar0[n0].idx:= m0][n1].idx:= m1] ∧ ar[n0, ar[n0].idx:= m0][n1, ar[n0, ar0[n0].idx:= m0][n1].idx:= m1][kar[m0, key-index(key0, n0)][m1, key-index(key1, n1)][m].idx].idx = m)
Used terms: n, ar[n0, ar[n0].idx:= m0][n1, ar[n0, ar0[n0].idx:= m0][n1].idx:= m1], kar[m0, key-index(key0, n0)][m1, key-index(key1, n1)]