This volume contains the papers presented at ADG 2012: The 9th International Workshop on Automated Deduction in Geometry, held on September 17–19, 2012 at the University of Edinburgh.

The submissions were each reviewed by at least 3 program committee members, and the committee decided to accept 15 papers for the workshop. The programme also included invited talks by Prof. Michael Beeson and Prof. Dong- ming Wang.

ADG 2012 is part of a well-established, international series of workshops. Previous editions of the meeting were held in Munich in 2010, Shanghai in 2008, Pontevedra in 2006, Gainesville in 2004, Hagenberg in 2002, Zurich in 2000, Beijing in 1998, and Toulouse in 1996.

We wish to thank the School of Informatics at the University of Edinburgh for hosting the workshop and for providing financial support and administrative help for the event. Support from EasyChair is also gratefully acknowledged.

Tetsuo Ida and Jacques Fleuriot
September 10, 2012 Edinburgh

Bibtex entry:

editor = {T. Ida and J. Fleuriot},
title = {Proceedings of the 9th International Workshop on Automated Deduction in Geometry (ADG 2012),
Edinburgh, September 17-19, 2012},
booktitle = {ADG 2012},
publisher = {University of Edinburgh},
series = {Informatics Research Report},
volume = {TBC},
note = {\url{}}