English
For any category C, the path construction composed with path composition yields the identity on C (in the unbundled sense): Paths.of C ⋙q (pathComposition C).toPrefunctor = 𝟭q C.
Русский
Для любой категории C построение путей, затем композиция путей, даёт тождество на C (в развернутом виде): Paths.of C ⋙q (pathComposition C).toPrefunctor = 𝟭q C.
LaTeX
$$$Paths.of C \;⋙q\; (pathComposition C).toPrefunctor = 𝟭q C$$$
Lean4
/-- An unbundled version of the right triangle equality. -/
theorem pathsOf_pathComposition_toPrefunctor (C : Type u) [Category.{v} C] :
Paths.of C ⋙q (pathComposition C).toPrefunctor = 𝟭q C :=
by
dsimp only [Prefunctor.comp]
congr
funext X Y f
exact Category.id_comp _