English
The left pi-congruence is compatible with taking symmetries: the inverse of piCongrLeft' is piCongrLeft' with the index equivalence inverted.
Русский
Левая pi-конгруэнтность совместима с взятием симметрии: обратное к piCongrLeft' равно piCongrLeft' с инверсией индексного эквивалентного отображения.
LaTeX
$$$$ \\big(\\text{piCongrLeft'}(R)\\ e\\big)^{-1} = \\text{piCongrLeft'}(R)\\ e^{-1}. $$$$
Lean4
@[simp]
theorem piCongrLeft'_symm {R : Type*} [NonUnitalNonAssocSemiring R] (e : α ≃ β) :
(RingEquiv.piCongrLeft' (fun _ => R) e).symm = RingEquiv.piCongrLeft' _ e.symm := by
simp only [piCongrLeft', RingEquiv.symm, MulEquiv.symm, Equiv.piCongrLeft'_symm]