English
There is an injectivity property for the map from Monoidal structures to LaxMonoidal structures on any functor F, i.e., different monoidal structures give different lax monoidal structures.
Русский
Существуют инъективные отображения между монодиями и ленс-модальными структурами функторов.
LaTeX
$$$$ \\operatorname{toLaxMonoidal\\_injective} $$$$
Lean4
theorem toOplaxMonoidal_injective :
Function.Injective (@Monoidal.toOplaxMonoidal _ _ _ _ _ _ _ : F.Monoidal → F.OplaxMonoidal) :=
by
intro a b eq
ext1
· rw [← cancel_mono (εIso _).inv]
rw [εIso_inv, ε_η, ← @ε_η _ _ _ _ _ _ _ a, ← εIso_inv]
exact congr(_ ≫ ($eq.symm).η)
· ext
rw [← cancel_mono (μIso F _ _).inv]
rw [μIso_inv, μ_δ, ← @μ_δ _ _ _ _ _ _ _ a, ← μIso_inv]
exact congr(_ ≫ ($eq.symm).δ _ _)
· exact congr(($eq).η)
· exact congr(($eq).δ)