#[global]
Hint Extern 4 (PreOrder (relation_disjunction _ _)) =>
class_apply StrictOrder_PreOrder : typeclass_instances.

Lemma StrictOrder_PartialOrder
`(Equivalence A eqA, StrictOrder A R, Proper _ (eqA==>eqA==>iffT) R) :
PartialOrder eqA (relation_disjunction R eqA).