Lean4
/-- Given two (in)equalities `P` and `Q`, look up the lemma to deduce `Q` from `P`, and the relation
appearing in the side condition produced by this lemma. -/
def relImpRelData : Ineq → Ineq → Option (Name × Ineq)
| eq, eq => some (``eq_of_eq, eq)
| eq, le => some (``Tactic.LinearCombination.le_of_eq, le)
| eq, lt => some (``lt_of_eq, lt)
| le, eq => none
| le, le => some (``le_of_le, le)
| le, lt => some (``lt_of_le, lt)
| lt, eq => none
| lt, le => some (``Tactic.LinearCombination.le_of_lt, le)
| lt, lt => some (``lt_of_lt, le)