English
The supremum of submodules indexed by i equals the range of the corresponding DirectSum coercion; equivalently, iSup_eq_toSubmodule_range.
Русский
Супремум подмодулей, индексируемых i, равен диапазону соответствующего DirectSum коэфф.
LaTeX
$$$$\\operatorname{iSup} \\; A = \\operatorname{Submodule}.toSubmodule(\\mathrm{DirectSum.coeAlgHom} A).range.$$$$
Lean4
@[simp]
theorem coeAlgHom_of [AddMonoid ι] [CommSemiring S] [Semiring R] [Algebra S R] (A : ι → Submodule S R)
[SetLike.GradedMonoid A] (i : ι) (x : A i) : DirectSum.coeAlgHom A (DirectSum.of (fun i => A i) i x) = x :=
DirectSum.toSemiring_of _ (by rfl) (fun _ _ => (by rfl)) _ _