fact: Definition O_monad_mult_natural {A B} (f : A -> B) : O_functor f o O_monad_mult A == O_monad_mult B o O_functor (O_functor f).
imports: HoTT.Basics HoTT.Types Equiv.BiInv Extensions HProp HFiber NullHomotopy Limits.Pullback PathAny Colimits.Pushout