~32768 ≤ i % 65536, i < 0, i < ~32768 ⊦ s2i(i2s(i)) = i % 65536
Used simplifier rules: ⊦ i < j ∧ ¬ i0 < j → ¬ i0 < i;% ⊦ ¬ i ≤ j ↔ j < i;