English
The coercion of the inverse of a unit matrix equals the nonsingular inverse.
Русский
Сведение обратной единицы матрицы к обычной матрице совпадает с несинговой обратной.
LaTeX
$$$\\uparrow (U^{-1}) = U^{-1}_{\\mathrm{ns}}$ for all $U \\in \\mathrm{Matrix}_n(\\alpha)^{\\times}$$$
Lean4
/-- Coercing the result of `Units.instInv` is the same as coercing first and applying the
nonsingular inverse. -/
@[simp, norm_cast]
theorem coe_units_inv (A : (Matrix n n α)ˣ) : ↑A⁻¹ = (A⁻¹ : Matrix n n α) :=
by
letI := A.invertible
rw [← invOf_eq_nonsing_inv, invOf_units]