XCB, the Last of the Shortest Single Axioms for the Classical Equivalential Calculus
Abstract
It has long been an open question whether the formula XCB = EpEEEpqErqr is, with the rules of substitution and detachment, a single axiom for the classical equivalential calculus. This paper answers that question affirmatively, thus completing a search for all such elevensymbol single axioms that began seventy years ago.
 Publication:

arXiv eprints
 Pub Date:
 November 2002
 arXiv:
 arXiv:cs/0211015
 Bibcode:
 2002cs.......11015W
 Keywords:

 Computer Science  Logic in Computer Science;
 Computer Science  Artificial Intelligence;
 F.4.1;
 I.2.3
 EPrint:
 6 pages, no figures