A synthetic proof of Pappus' theorem in Tarski's geometry - Inria - Institut national de recherche en sciences et technologies du numérique Access content directly
Journal Articles Journal of Automated Reasoning Year : 2017

A synthetic proof of Pappus' theorem in Tarski's geometry


In this paper, we report on the formalization of a synthetic proof of Pappus' theorem. We provide two versions of the theorem: the first one is proved in neutral geometry (without assuming the parallel postulate), the second (usual) version is proved in Euclidean geometry. The proof that we formalize is the one presented by Hilbert in The Foundations of Geometry which has been detailed by Schwabhäuser , Szmielew and Tarski in part I of Metamathematische Methoden in der Geometrie. We highlight the steps which are still missing in this later version. The proofs are checked formally using the Coq proof assistant. Our proofs are based on Tarski's axiom system for geometry without any continuity axiom. This theorem is an important milestone toward obtaining the arithmetization of geometry which will allow us to provide a connection between analytic and synthetic geometry.
Fichier principal
Vignette du fichier
Pappus.pdf (339.87 Ko) Télécharger le fichier
Origin : Files produced by the author(s)

Dates and versions

hal-01176508 , version 1 (15-07-2015)
hal-01176508 , version 2 (31-03-2016)


Attribution - NonCommercial - NoDerivatives



Gabriel Braun, Julien Narboux. A synthetic proof of Pappus' theorem in Tarski's geometry. Journal of Automated Reasoning, 2017, 58 (2), pp.23. ⟨10.1007/s10817-016-9374-4⟩. ⟨hal-01176508v2⟩
401 View
1258 Download



Gmail Facebook X LinkedIn More