| i ∈ ints0, perm(ints1, ints0 -1l i), perm(ints1, ints0 -1l i) → max(ints1) = max(ints0 -1l i) ⊦ ints1 = [], max(i, max(ints1)) = max(ints0) |
max(ints1) = max(ints0 -1l i), i ∈ ints0, perm(ints1, ints0 -1l i) ⊦ ints1 = [], max(i, max(ints1)) = max(ints0)