instance
PushforwardExactAffine.restrictScalars_preservesFiniteLimits
{R S : Type v}
[CommRing R]
[CommRing S]
(φ : R →+* S)
:
Restriction of scalars along a ring homomorphism preserves finite limits (it is a right adjoint to extension of scalars).
instance
PushforwardExactAffine.restrictScalars_preservesFiniteColimits
{R S : Type v}
[CommRing R]
[CommRing S]
(φ : R →+* S)
:
Restriction of scalars along a ring homomorphism preserves finite colimits (it is a left adjoint to coextension of scalars).
theorem
PushforwardExactAffine.restrictScalars_exact
{R S : Type v}
[CommRing R]
[CommRing S]
(φ : R →+* S)
:
Restriction of scalars is exact: it preserves both finite limits and finite colimits.
instance
PushforwardExactAffine.pushforward_preservesFiniteLimits
{X Y : AlgebraicGeometry.Scheme}
(f : X ⟶ Y)
:
The pushforward of modules along a morphism of schemes preserves finite limits
(left-exactness of f_*).