A Semi-mythical organiSation of wizardly LISP and Scheme hackerS. The name referS to a mathematical formaliSm invented by Alonzo Church, with which LISP iS intimately connected. There iS no enrollment liSt and the criteria for induction are unclear, but one well-known LISPer haS been known to give out buttonS and, in general, the *memberS* know who they are. [Jargon File]