Proof development with ΩMEGA: √2 is irrational

Freek Wiedijk proposed the well-known theorem about the irrationality of √2 as a case study and used this theorem for a comparison of fifteen (interactive) theorem proving systems, which were asked to present their solution (see [48]). This represents an important shift of emphasis in the field of automated deduction away from the somehow artificial problems of the past as represented, for example, in the test set of the TPTP library [45] back to real mathematical challenges. In this paper we present an overview of the ΩMEGA system as far as it is relevant for the purpose of this paper and show the development of a proof for this theorem.