English
For HasCoequalizer f g and HasCoequalizer (G.map f) (G.map g), the projection composed with coequalizerComparison and then coequalizer.desc equals G.map (coequalizer.π f g).
Русский
Пусть существуют коэквалайзер f g и коэквалайзер (G.map f) (G.map g). Тогда π (G.map f) (G.map g) ≫ coequalizerComparison f g G = G.map (coequalizer.π f g).
LaTeX
$$$ coequalizer.\\pi (G.map f) (G.map g) \\; \\circ \\; coequalizerComparison f g G = G.map (coequalizer.\\pi f g) $$$
Lean4
@[reassoc (attr := simp)]
theorem ι_comp_coequalizerComparison [HasCoequalizer f g] [HasCoequalizer (G.map f) (G.map g)] :
coequalizer.π _ _ ≫ coequalizerComparison f g G = G.map (coequalizer.π _ _) :=
coequalizer.π_desc _ _