English
The top Boolean subalgebra ⊤ of α is isomorphic to α itself, via an order isomorphism to the underlying set.
Русский
Верхняя булева подпалгебра ⊤ α изоморфна α саму по себе через порядок-изоморфизм к базовому множеству.
LaTeX
$$topEquiv : (⊤ : BooleanSubalgebra α) ≃o α$$
Lean4
/-- The top Boolean subalgebra is isomorphic to the original Boolean algebra.
This is the Boolean subalgebra version of `Equiv.Set.univ α`. -/
def topEquiv : (⊤ : BooleanSubalgebra α) ≃o α
where
toEquiv := Equiv.Set.univ _
map_rel_iff' := .rfl