an:01089469
Zbl 0883.06011
McCune, William
Solution of the Robbins problem
EN
J. Autom. Reasoning 19, No. 3, 263-276 (1997).
00043784
1997
j
06E05 68T15 06-04
associative-commutative unification; paramodulation; Robbins algebra; commutativity; associativity; Robbins equation; variety of Boolean algebras; EQP; theorem-proving program for equational logic; search strategies
Summary: We show that the three equations known as commutativity, associativity, and the Robbins equation are a basis for the variety of Boolean algebras. The problem was posed by Herbert Robbins in the 1930s. The proof was found automatically by EQP, a theorem-proving program for equational logic. We present the proof and the search strategies that enabled the program to find the proof.