⊦ i < 0 → i→n(i) = i→n(~ i)
i < 0, i→n(~(i - 1)) < i→n(i), i - 1 < 0 ⊦
Used simplifier rules: ⊦ i - j < i0 ↔ i < j + i0; (s)% ⊦ i < j ↔ ¬ j ≤ i; (ss)% ⊦ 1 ≤ i ↔ 0 < i; (s)% ⊦ i < j → ¬ j < i; (s) Used terms: i - 1