Short Proofs of Tautologies Using the Schema of Equivalence.

Matthias Baaz Richard Zach Short Proofs of Tautologies Using the Schema of Equivalence. 33-35 1993 conf/csl/1993 CSL db/conf/csl/csl93.html#BaazZ93 http://dx.doi.org/10.1007/BFb0049322