Differences
This shows you the differences between two versions of the page.
Both sides previous revision Previous revision Next revision | Previous revision Next revision Both sides next revision | ||
hom-set_adjunction [2016/02/11 13:15] nikolaj |
hom-set_adjunction [2016/02/11 13:22] nikolaj |
||
---|---|---|---|
Line 32: | Line 32: | ||
== Idea == | == Idea == | ||
- | More generally, view the left adjoint $F$ as A-"thickening" of ist argument ($X$) and view $G$ as the A-indexing of aspects of it's argument $Y$. | + | More generally, |
+ | view the left adjoint $F$ as A-"thickening" of ist argument ($X$) and view $G$ as the A-indexing of aspects of it's argument $Y$. | ||
+ | |||
+ | If ${\bf C}\neq{\bf D}$, then viewing $G$ as indexing may be harder. | ||
== Example from Algebra == | == Example from Algebra == | ||
Line 70: | Line 73: | ||
$(A\times Y^A)$ to $Y$. | $(A\times Y^A)$ to $Y$. | ||
- | The first can only be | + | The first can only be a direct embedding |
$\eta_Y(y):=\lambda a.\, \langle a,y\rangle$ | $\eta_Y(y):=\lambda a.\, \langle a,y\rangle$ | ||
- | and the second | + | and the second is an evaluation |
$\epsilon_Y(\langle a,f\rangle) := f(a)$ | $\epsilon_Y(\langle a,f\rangle) := f(a)$ |