Revision as of 17:23, 4 November 2009
IMPORTANT NOTE: THESE NOTES ARE STILL UNDER DEVELOPMENT. PLEASE WAIT UNTIL AFTER THE LECTURE WITH HANDING ANYTHING IN, OR TREATING THE NOTES AS READY TO READ.
1 Some adjunctions we already know
- initial/terminal are adjunctions.
- (co)-products are adjunctions.
- Actually, all (co)limits are adjunctions.
2 Some adjunctions we don't know yet
- Existential and universal qualifiers as adjunctions.
- Powersets and im(f) -| f^\inv
3 Properties of adjoints
3.1 RAPL: Right Adjoints Preserve Limits
3.2 Recognizing adjoints
Theorem (Freyd: The Adjoint Functor Theorem)