English
Every monoid homomorphism F : WithOne α →* β is equal to lift of its restriction to α, i.e. F = lift (F.toMulHom.comp coeMulHom).
Русский
Любой моноид-гомоморфизм F : WithOne α →* β равен подъему lift от ограничение F к α: F = lift (F.toMulHom.comp coeMulHom).
LaTeX
$$$F = \mathrm{lift}(F^{\mathrm{toMulHom}} \circ \mathrm{coeMulHom})$$$
Lean4
@[to_additive]
theorem lift_unique (f : WithOne α →* β) : f = lift (f.toMulHom.comp coeMulHom) :=
(lift.apply_symm_apply f).symm