Showing Proofs, Assessing Difficulty with GeoGebra Discovery
Zoltán Kovács, Tomás Recio, M. Pilar Vélez
TL;DR
The paper addresses the challenge of making automated geometric proofs in GeoGebra Discovery transparent by introducing ShowProof, which visualizes the algebraic reasoning steps and certificates, and by proposing a syzygy-based difficulty metric for geometric statements. It formalizes a complexity measure where the difficulty of a statement H ⇒ T is tied to the maximum degree of the syzygies expressing T (or $1$) as a combination of the hypotheses, and it employs the Rabinowitsch trick to certify ideal membership. Through three illustrative examples, the authors demonstrate how the certificate and its degree depend on equation representations and numerical specialization, revealing that the same geometric claim can exhibit different measured complexities. The work lays groundwork for evaluating and comparing automated geometric proofs and suggests further exploration into more complex problems and the theoretical relationship between expression complexity and decidability in this algebraic geometric framework.
Abstract
In our contribution we describe some on-going improvements concerning the Automated Reasoning Tools developed in GeoGebra Discovery, providing different examples of the performance of these new features. We describe the new ShowProof command, that outputs both the sequence of the different steps performed by GeoGebra Discovery to confirm a certain statement, as well as a number intending to grade the difficulty or interest of the assertion. The proposal of this assessment measure, involving the comparison of the expression of the thesis (or conclusion) as a combination of the hypotheses, will be developed.
