nLab
cofiber

Contents

Contents

Definition

Lemma

For f:ABf : A \to B a morphism in a category with a terminal object, the cofiber of ff is the cofiber coproduct of ff with the terminal morphism, hence the pushout

A f B * B A*. \array{ A &\stackrel{f}{\to}& B \\ \downarrow && \downarrow \\ * &\to& B \coprod_A * } \,.

Examples

Cokernels

In an additive category cofibers over the zero object are called cokernels.

Created on September 12, 2012 at 19:04:14. See the history of this page for a list of all contributions to it.