feat(algebra/algebra/subalgebra): `subalgebra.map` commutes with supremum (#10899)
feat(algebra/algebra/subalgebra): `subalgebra.map` commutes with supremum (#10899)

This PR proves `(S ⊔ T).map f = S.map f ⊔ T.map f`.



Co-authored-by: tb65536 <25c750517795e47f172dc8c552ed72c7de260bd4@users.noreply.github.com>

leanprover-community/mathlib,leanprover-community/mathlib