Definitions
1.AdjectiveWhich reverses the order of morphism composition: formally, which associates each morphism
f
:
X
→
Y
{\displaystyle f:X\to Y}
to a morphism
F
(
f
)
:
F
(
Y
)
→
F
(
X
)
{\displaystyle F(f):F(Y)\to F(X)}
.
2.AdjectiveUsing or relating to contravariance.
3.AdjectiveScaling inversely with a change of basis.
4.NounA bihomogeneous polynomial in dual variables of x, y, ... and the coefficients of some homogeneous form in x, y, ... that is invariant under some group of linear transformations.