Stream: Archive Mirror: Isabelle Users Mailing List

Topic: [isabelle] new in the AFP: Buildings


view this post on Zulip Email Gateway (Aug 22 2022 at 13:40):

From: Gerwin Klein <Gerwin.Klein@nicta.com.au>
A new AFP entry is online at https://www.isa-afp.org

Chamber Complexes, Coxeter Systems, and Buildings
by Jeremy Sylvestre

We provide a basic formal framework for the theory of chamber complexes and Coxeter systems, and for buildings as thick chamber complexes endowed with a system of apartments. Along the way, we develop some of the general theory of abstract simplicial complexes and of groups (relying on the group_add class for the basics), including free groups and group presentations, and their universal properties. The main results verified are that the deletion condition is both necessary and sufficient for a group with a set of generators of order two to be a Coxeter system, and that the apartments in a (thick) building are all uniformly Coxeter.

https://www.isa-afp.org/entries/Buildings.shtml

Enjoy!
Gerwin


The information in this e-mail may be confidential and subject to legal professional privilege and/or copyright. National ICT Australia Limited accepts no liability for any damage caused by this email or its attachments.


Last updated: Apr 30 2024 at 01:06 UTC