Conditions arising in the study of the Robbins Equation and its connection with Boolean Algebra. Winkler
studied Boolean conditions (such as idempotence or existence of a zero) which would make a Robbins Algebra become
a Boolean Algebra. Winkler showed that each of the conditions

known as the first and second Winkler conditions, Suffices. A computer proof demonstrated that every Robbins Algebra satisfies the second Winkler condition, from which it follows immediately that all Robbins Algebras are Boolean.

**References**

McCune, W. ``Robbins Algebras are Boolean.'' http://www-unix.mcs.anl.gov/~mccune/papers/robbins/.

Winkler, S. ``Robbins Algebra: Conditions that Make a Near-Boolean Algebra Boolean.'' *J. Automated Reasoning*
**6**, 465-489, 1990.

Winkler, S. ``Absorption and Idempotency Criteria for a Problem in Near-Boolean Algebra.'' *J. Algebra* **153**,
414-423, 1992.

© 1996-9

1999-05-26