⊦ ar1 = ar2 ↔ # ar1 = # ar2 ∧ (∀ n. n < # ar1 → ar1[n] = ar2[n])
⊦ # ar[n, a] = # ar[n, b] ∧ (∀ n0. n0 < # ar[n, a] → ar[n, a][n0] = ar[n, b][n0]) ↔ n < # ar → a = b
Used terms: ar[n, b], ar[n, a]