English
The with-one congruence of the reflexive equal is equal to the reflexive in WithOne: (MulEquiv.refl α).withOneCongr = MulEquiv.refl (WithOne α).
Русский
Соответствие с единицей сохраняется в пределах WithOne для тождества: (MulEquiv.refl α).withOneCongr = MulEquiv.refl (WithOne α).
LaTeX
$$$(\mathrm{MulEquiv.refl}\ \alpha).\mathrm{withOneCongr} = \mathrm{MulEquiv.refl}\ (\mathrm{WithOne}\ \alpha)$$$
Lean4
@[to_additive (attr := simp)]
theorem _root_.MulEquiv.withOneCongr_refl : (MulEquiv.refl α).withOneCongr = MulEquiv.refl _ :=
MulEquiv.toMonoidHom_injective mapMulHom_id