Volume no :3, Issue no: 2, May (2010)

PARTIAL MONOIDS: ASSOCIATIVITY AND CONFLUENCE

Author's: Laurent Poinsot, Gérard H. E. Duchamp and Christophe Tollu
Pages: [265] - [285]
Received Date: May 28, 2010
Submitted by:

Abstract

A partial monoid P is a set with a partial multiplication (and total identity ), which satisfies some associativity axiom. The partial monoid P may be embedded in the free monoid and the product is simulated by a string rewriting system on that consists in evaluating the concatenation of two letters as a product in P, when it is defined, and a letter as the empty word In this paper, we study the profound relations between confluence for such a system and associativity of the multiplication. Moreover, we develop a reduction strategy to ensure confluence, and which allows us to define a multiplication on normal forms associative up to a given congruence of Finally, we show that this operation is associative, if and only if, the rewriting system under consideration is confluent.

Keywords

partial monoid, string rewriting system, normal form, associativity and confluence.