Matthias Baaz, Richard Zach. Short Proofs of Tautologies Using the Schema of Equivalence. In Egon Börger, Yuri Gurevich, Karl Meinke, editors, Computer Science Logic, 7th Workshop, CSL 93, Swansea, United Kingdom, September 13-17, 1993, Selected Papers. Volume 832 of Lecture Notes in Computer Science, pages 33-35, Springer, 1993.
Abstract is missing.