# Contents

## Definition

A homotopical functor $F : C \to D$ between two homotopical categories $C$ and $D$ is a functor which preserves the weak equivalences of $C$ (i.e., which sends all weak equivalences of $C$ to weak equivalences of $D$).

Revised on August 17, 2011 17:52:15 by Urs Schreiber (194.81.173.218)