English
There is an order isomorphism between Subalgebra R A and Subalgebra R Aᵐᵒᵖ, given by op and unop.
Русский
Существует упорядоченное изоморфное отображение между Subalgebra R A и Subalgebra R A^{op}, задаваемое операциями op и unop.
LaTeX
$$$ \operatorname{opEquiv} : \mathrm{Subalgebra}(R,A) \simeq_{\mathrm{ord}} \mathrm{Subalgebra}(R, A^{\mathrm{op}}). $$$
Lean4
/-- A subalgebra `S` of `A / R` determines a subalgebra `S.op` of the opposite ring `Aᵐᵒᵖ / R`. -/
@[simps]
def opEquiv : Subalgebra R A ≃o Subalgebra R Aᵐᵒᵖ
where
toFun := Subalgebra.op
invFun := Subalgebra.unop
left_inv := unop_op
right_inv := op_unop
map_rel_iff' := op_le_op_iff