English
Reiterates that a relative cell complex can be expressed as a transfinite composition of pushouts of coproducts over a shape J.
Русский
Повторяет, что относительный клеточный комплекс может быть выражен как трансфинитная композиция пушаутов копроподс по форме J.
LaTeX
$$$\text{transfiniteCompositionOfShape}$$$
Lean4
/-- If `f` is a relative cell complex with respect to a constant
family of morphisms `g`, then `f` is a transfinite composition
of pushouts of coproducts of morphisms in the family `g`. -/
@[simps toTransfiniteCompositionOfShape]
def transfiniteCompositionOfShape {α : Type*} {A B : α → C} (g : (i : α) → (A i ⟶ B i))
(c : RelativeCellComplex.{w} (fun (_ : J) ↦ g) f) :
(coproducts.{w} (ofHoms g)).pushouts.TransfiniteCompositionOfShape J f
where
toTransfiniteCompositionOfShape := c.toTransfiniteCompositionOfShape
map_mem j hj := (c.attachCells j hj).pushouts_coproducts