⊦ ¬ i < j ↔ ¬ ¬(i = j ∨ j < i)
Used simplifier rules: l: ⊦ ¬ i < j ↔ ¬ ¬(i = j ∨ j < i);%ls-02: ⊦ i < 1 ∧ i ≠ 0 → i < 0;%ls-01: ⊦ i < j → ¬ j < i; Used terms: j, 0