English
There exists a canonical right Kan extension for L and F.
Русский
Существует каноничное правое кан-расширение для L и F.
LaTeX
$$$\operatorname{HasRightKanExtension}(L,F)$$$
Lean4
/-- Alternative constructor for `PreservesLeftKanExtension`, phrased in terms of
`LeftExtension.IsUniversal` instead. See `PreservesLeftKanExtension.mk_of_preserves_isUniversal`
for a similar constructor taking as input a single `LeftExtension`. -/
theorem mk'
(preserves :
∀ {E : LeftExtension L F}, E.IsUniversal → Nonempty (LeftExtension.postcompose₂ L F G |>.obj E).IsUniversal) :
G.PreservesLeftKanExtension F L where
preserves _ _
h :=
⟨⟨Limits.IsInitial.equivOfIso (LeftExtension.postcompose₂ObjMkIso _ _) <|
(preserves h.nonempty_isUniversal.some).some⟩⟩