The MPTP $100 Challenges are sets of classical first-order reasoning problems, expressed in the TpTP language, to be proved by fully automated reasoning systems, within specified reasonable resource constraints. The challenge problems are based on the Mizar Mathematical Library, see http://www.cs.miami.edu/~tptp/MPTPChallenge/ for details, and also MpTPChallengeFAQ.
-- JosefUrban - 10 Nov 2006