English
The forgetful functor from rings to additive commutative groups preserves all limits.
Русский
Функтор забывания из колец к аддитивным коммутативным группам сохраняет все пределы.
LaTeX
$$$\mathrm{forget}_2: \text{RingCat} \to \text{AddCommGrpCat}$ preserves limits of size.$$
Lean4
/-- The forgetful functor from rings to additive commutative groups preserves all limits.
-/
instance forget₂AddCommGroup_preservesLimitsOfSize [UnivLE.{v, u}] :
PreservesLimitsOfSize.{v, v} (forget₂ RingCat.{u} AddCommGrpCat.{u}) where
preservesLimitsOfShape
{_
_} :=
{
preservesLimit := fun {F} =>
preservesLimit_of_preserves_limit_cone (limitConeIsLimit.{v, u} F) (forget₂AddCommGroupPreservesLimitsAux F) }