English
If F preserves limits of a given size after forgetting, then F preserves limits of that size.
Русский
Если F сохраняет пределы заданного размера после забывания, то F сохраняет пределы этого размера.
LaTeX
$$$\operatorname{PreservesLimitsOfSize}(F) \Leftarrow \operatorname{PreservesLimitsOfSize}(F \circ \mathrm{forget}).$$$
Lean4
/-- `F : C ⥤ Action V G` preserves limits of some size
if it does after postcomposing with the forgetful functor `Action V G ⥤ V`. -/
theorem preservesLimitsOfSize_of_preserves (F : C ⥤ Action V G)
(h : PreservesLimitsOfSize.{w₂, w₁} (F ⋙ Action.forget V G)) : PreservesLimitsOfSize.{w₂, w₁} F :=
by
constructor
intro J _
apply Action.preservesLimitsOfShape_of_preserves
exact PreservesLimitsOfSize.preservesLimitsOfShape