English
There is a canonical X ⟶ P given P and a factorization h via P; i.e., factorThrough returns a map X ⟶ P.
Русский
Существует канонический морфизм X ⟶ P, задаваемый через P и факторизацию h (через P).
LaTeX
$$$P \\mapsto \\mathrm{factorThru}(X,Y,P,f,h) : X \\to P$$$
Lean4
/-- `P.factorThru f h` provides a factorisation of `f : X ⟶ Y` through some `P : Subobject Y`,
given the evidence `h : P.Factors f` that such a factorisation exists. -/
def factorThru {X Y : C} (P : Subobject Y) (f : X ⟶ Y) (h : Factors P f) : X ⟶ P :=
Classical.choose ((factors_iff _ _).mp h)