11

Here are two missing elements: 11, and relation complement ^A.

Axioms:
A join ^A = 00 join A
A union ^A = 11 union A

00 join 11 = 10
00 union 11 = 01

Needless to say that ^A is a basis for clean definition of minus operator. Received on Tue Aug 23 2005 - 19:06:38 CDT