English
The flat sections of a functor into ModuleCat R form a submodule of all sections.
Русский
Плоские секции непрерывной функции в ModuleCat R образуют подмодуль всех секций.
LaTeX
$$$$ \\text{sectionsSubmodule}(F) \\subseteq (\\text{sections}) $$$$
Lean4
/-- The flat sections of a functor into `ModuleCat R` form a submodule of all sections.
-/
def sectionsSubmodule : Submodule R (∀ j, F.obj j) :=
{
AddGrpCat.sectionsAddSubgroup.{v, w}
(F ⋙
forget₂ (ModuleCat R) AddCommGrpCat.{w} ⋙
forget₂ AddCommGrpCat
AddGrpCat.{w}) with
carrier := (F ⋙ forget (ModuleCat R)).sections
smul_mem' := fun r s sh j j' f => by simpa [Functor.sections, forget_map] using congr_arg (r • ·) (sh f) }