Homotopy Type Theory effective epic function > history (Rev #5)

Definition

Given types AA and BB, a function f:ABf:A \to B is a effective epic function if for all terms b:Bb:B the fiber of ff over bb is inhabited.

isEffectiveEpic(f) b:Bfiber(f,b)isEffectiveEpic(f) \coloneqq \prod_{b:B} \Vert fiber(f, b) \Vert

The type of effective epic functions between AA and BB is defined as

EffectiveEpic(A,B) f:ABisEffectiveEpic(f)EffectiveEpic(A, B) \coloneqq \sum_{f:A \to B} isEffectiveEpic(f)

Examples

  • The surjections f:ABf:A \to B between two sets AA and BB are effective epic functions.

See also

Revision on June 15, 2022 at 22:51:01 by Anonymous?. See the history of this page for a list of all contributions to it.