fact: Definition isequiv_O_prod_unit_precompose {fs : Funext} (A B C : Type) `{In O C} : IsEquiv (fun (f : (O A) * (O B) -> C) => f o O_prod_unit A B).
imports: HoTT.Basics HoTT.Types Equiv.BiInv Extensions HProp HFiber NullHomotopy Limits.Pullback PathAny Colimits.Pushout