English
A particular equality between piComparison and forkMap holds, after unfolding forkMap and using the coproduct–product isomorphism.
Русский
Утверждается равенство между piComparison и forkMap после раскрытия forkMap и использования изоморфности копроизвестие–произведение.
LaTeX
$$$\text{piComparison}_F = F.map(\mathrm{opCoproductIsoProduct}'\,hc\,\mathrm{(productIsProduct }\_\text{)} ).inv \circ Equalizer.Presieve.Arrows.forkMap F X c.inj$$$
Lean4
@[reassoc (attr := simp)]
theorem toSheafify_naturality {P Q : Cᵒᵖ ⥤ D} (η : P ⟶ Q) : η ≫ toSheafify J _ = toSheafify J _ ≫ sheafifyMap J η :=
sheafificationAdjunction J D |>.unit.naturality η