English
The singular chain complex functor with coefficients in C is a functor from C to the functor category SSet ⥤ ChainComplex C ℕ.
Русский
Сурр singular chain complex functor с коэффициентами в C есть функтор от C к функторной категории SSet ⥤ ChainComplex C ℕ.
LaTeX
$$$$ \mathrm{singularChainComplexFunctor} : C \to \big(\mathrm{SSet} \to \mathrm{ChainComplex} C \mathbb{N} \big) $$$$
Lean4
/-- The singular chain complex associated to a simplicial set, with coefficients in `X : C`.
One can recover the ordinary singular chain complex when `C := Ab` and `X := ℤ`.
-/
def singularChainComplexFunctor : C ⥤ SSet.{w} ⥤ ChainComplex C ℕ :=
(Functor.postcompose₂.obj (AlgebraicTopology.alternatingFaceMapComplex _)).obj
(sigmaConst ⋙ SimplicialObject.whiskering _ _)