# Contents

## Idea

A cohesive ∞-groupoid is formal if all its spaces of k-morphism have infinitesimal extension. If they have first order infinitesimal extension, the formal cohesive $\infty$-groupoid is an ∞-Lie algebroid.

## Definition

For the moment see the section Formal cohesive ∞-groupoids at cohesive (∞,1)-topos .

## Examples

### Special cases

A 1-truncated formal cohesive $\infty$-groupoid is a formal groupoid. If the space of objects is the terminal object, this is the delooping of a formal group.

More generally, if the space of objects of a formal cohesvive $\infty$-groupoid is the terminal object, it is the delooping of a formal ∞-group .

Created on April 13, 2011 21:56:53 by Urs Schreiber (82.113.99.35)