Tarski's geometry. http://dpt-info.u-strasbg.fr/~narboux/tarski.html This is a formalization of geometry using a simplified version of Tarski's axiom system. The development contains a formalization of the chapters 1-8 of the book "Metamathematische Methoden in der Geometrie" by W. Schwabhäuser, W. Szmielew and A. Tarski. This includes between properties, congruence properties, midpoint, perpendicular lines, point reflection, orthogonality ... This development aims to be a low level complement for Frédérique Guilhot's development about high-school geometry. For more information see: Mechanical Theorem Proving in Tarski's geometry in the post-proceeding of ADG 2006, F. Botana and T. Recio (Eds.), LNAI 4869, pages 139-156, 2007.
opam install coq-tarski-geometry.8.7.0