Open problems about regular languages 35 years later PDF

We give a new proof that the polynomial closure of a lattice of regular languages closed under quotient is also closed under intersection. 2. We prove a

Polynomial closure and unambiguous product

languages are classes of recognizable languages closed under finite boolean. *LITP/IBP Université Paris VI et CNRS

A The Tale of the Quantifier Alternation Hierarchy of First-Order

order logic: it is about the class of star-free languages. This is the smallest class of languages containing all finite languages and closed under boolean

Simple Representations of Certain Classes of Languages

linear context-free language ~s a homomorphic replication of type p of some regular set. Thus the class of regular sets ts not closed under homomorphic

Duality and equational theory of regular languages

22 nov. 2008 and Priestley duality. Let us call lattice of languages a class of regular languages closed under finite intersection and finite union.

Classes of Languages Generated by the Kleene Star of a Word

a Boolean algebra) of regular languages closed under quotients. Equations with zero. The existence of a zero in a syntactic monoid is given by the equations:.

Languages and formations generated by D4 and Q8

Recall that a formation of groups is a class of finite groups closed under taking quotients and subdirect products. This question was motivated by the

Polynomial closure and unambiguous product

23 déc. 2015 languages and varieties of finite semigroups or finite monoids. Varieties of languages are classes of recognizable languages closed under ...