The syntactic monoid of a language is generalized to the level of a symmetric monoidal closed category D. This allows for a uniform treatment of several notions of syntactic algebras known in the literature, including the syntactic monoids of Rabin and Scott (D “ sets), the syntactic semirings of Polák (D “ semilattices), and the syntactic associative algebras of Reutenauer (D = vector spaces)....

Generalizing results of Otto & Ruškuc, this paper shows that every finitely generated submonoid of a monoid presented by a confluent finite special rewriting system admits an automatic structure that is simultaneously rr-, `r-, r`-, and ``-automatic; and that every finitely generated submonoid of a monoid presented by a confluent regular monadic rewriting system admits an automatic structure th...

Pierre McKenzie and Sambuddha Roy pointed out that the proof of statements (b) and (c) in Theorem 7.3 are buggy. The main flaw is that the identity e of the group F may not be the identity of the monoid, and so the claim that w ∈ (A F,r) * ⇐⇒ w ∈ Test does not work. In this corrigendum, we show: • With a slight change to Definition 7.1, the statement of Theorem 7.3 holds unchanged. In our opini...

In this paper, a Gröbner-Shirshov basis for the Chinese monoid is obtained and an algorithm for the normal form of the Chinese monoid is given. AMS Mathematics Subject Classification (2000): 16S15, 16S35, 20M25.

We deene a standard of eeectiveness for a database calculus relative to a query language. EEectiveness judges suitability to serve as a processing framework for the query language, and comprises aspects of coverage, manipulability and eecient evaluation. We present the monoid calculus, and argue its eeectiveness for object-oriented query languages, exempliied by OQL of ODMG-93. The monoid calcu...

An endomorphism of the free monoid A∗ is invertible if it is injective and extends to an automorphism of the free group generated by A. A simple example: the endomorphism that leaves all generators A invariant except one, say a, which is mapped to ba for some other generator b. We give a monoid presentation for the submonoid generated by all such endomorphisms when a and b are taken arbitrarily...

We described in [7] a monoid b G acting on the integrable highest weight modules of a symmetrizable Kac-Moody algebra. It has similar structural properties as a reductive algebraic monoid with unit group a Kac-Moody group G. Now we find natural extensions of the action of the Kac-Moody group G on its building Ω to actions of the monoid b G on Ω. These extensions are partly motivated by represen...

We discuss unique decomposition in partial commutative monoids. Inspired by a result from process theory, we propose the notion of decomposition order for partial commutative monoids, and prove that a partial commutative monoid has unique decomposition iff it can be endowed with a decomposition order. We apply our result to establish that the commutative monoid of weakly normed processes modulo...

The aim of this paper is sketch a theory of divisibility and factorisation in topological monoids, where finite products are replaced by convergent products. The algebraic case can then be viewed as the special case of discretely topologised topological monoids. In particular, we define the topological factorisation monoid, a generalisation of the factorisation monoid for algebraic monoids, and...

We provide a new algebraic description of the structure on the set of all unstable cohomology operations for a suitable generalised cohomology theory, E(−). Our description is as a graded and completed version of a Tall-Wraith monoid. The E-cohomology of a space X is a module for this Tall-Wraith monoid. We also show that the corresponding Hopf ring of unstable co-operations is a module for the...