6 papers
Formulas generalizing Pappus and Desargues
Roger D. Maddux
The Theorems of Pappus and Desargues are generalized by two special formulas that hold in the three-dimensional vector space over a field.
Tarskian classical relevant logic
Roger D. Maddux
The Tarskian classical relevant logic TR arises from Tarski's work on the foundations of the calculus of relations and on first-order logic restricted to finitely many variables, p…
Tarski's relevance logic; Version 2
Roger D. Maddux
Tarski's relevance logic is defined and shown to contain many formulas and derived rules of inference. The definition arises from Tarski's work on first-order logic restricted to f…
Relation algebras of Sugihara, Belnap, Meyer, and Church
Richard L. Kramer, Roger D. Maddux
Algebras introduced by, or attributed to, Sugihara, Belnap, Meyer, and Church are representable as algebras of binary relations with set-theoretically defined operations. They are…
Finite representations for two small relation algebras
Jeremy F. Alm, Roger D. Maddux
In this note, we give two different proofs that relation algebra is representable over a finite set. The first is probabilistic, and uses Johnson schemes. The second is a…
The finite representation property fails for composition and intersection
Roger D. Maddux
The title theorem is proved by example: an algebra of binary relations, closed under intersection and composition, that is not isomorphic to any such algebra on a finite set.