fact: Definition cancelR_isequiv_mapinO {A B C : Type} (f : A -> B) (g : B -> C) `{IsEquiv _ _ f} `{MapIn O _ _ (g o f)} : MapIn O g.
imports: HoTT.Basics HoTT.Types Equiv.BiInv Extensions HProp HFiber NullHomotopy Limits.Pullback PathAny Colimits.Pushout