nLab cofiber

Context

Limits and colimits

limits and colimits

Contents

Definition

Lemma

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

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

Examples

Cokernels

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

Created on September 12, 2012 19:04:38 by Urs Schreiber (131.174.188.61)