| ⊦ no-dups-idx(kar, n) ∧ kar[m0] = ki0 ∧ kar[m1] = ki1 ∧ m0 < n ∧ m1 < n ∧ m0 < # kar ∧ m1 < # kar → no-dups-idx(kar[m0, ki1][m1, ki0], n) |
kar[m0] = ki0, kar[m1] = ki1, m0 < n, m1 < n, m0 < # kar, m1 < # kar, no-dups-idx(kar, n) ⊦ no-dups-idx(kar[m0, ki1][m1, ki0], n)