Events in natural language semantics are characterized in terms of regular languages, each string in which can be regarded as a temporal sequence of observations. The usual regular constructs (concatenation, etc.) are supplemented with superposition, inducing a useful notion of entailment, distinct from that given by models of predicate logic.

A language L over an alphabet Σ is suffix-convex if, for any words x, y, z ∈ Σ∗, whenever z and xyz are in L, then so is yz. Suffixconvex languages include three special cases: left-ideal, suffix-closed, and suffix-free languages. We examine complexity properties of these three special classes of suffix-convex regular languages. In particular, we study the quotient/state complexity of boolean o...

Let U be a numeration system, a set X ⊆ N is U -star-free if the set made up of the U -representations of the elements in X is a star-free regular language. Answering a question of A. de Luca and A. Restivo [10], we obtain a complete logical characterization of the U -star-free sets of integers for suitable numeration systems related to a Pisot number and in particular for integer base systems....

In this paper, we introduce the notions of product vague graph, balanced product vague graph, irregularity and total irregularity of any irregular vague graphs and some results are presented. Also, density and balanced irregular vague graphs are discussed and some of their properties are established. Finally we give an application of vague digraphs.

We define a class of languages of infinite words over infinite alphabets, and the corresponding automata. The automata used for recognition are a generalisation of deterministic Muller automata to the setting of nominal sets. Remarkably, the obtained languages are determined by their ultimately periodic fragments, as in the classical case. Closure under complement, union and intersection, and d...

We investigate the complexity of deciding whether a given regular language can be defined with a deterministic regular expression. Our main technical result shows that the problem is PSPACE-complete if the input language is represented as a regular expression or nondeterministic finite automaton. The problem becomes EXPSPACE-complete if the language is represented as a regular expression with c...

The purpose of present work is to study some algebraic aspect of fuzzy multiset regular languages. In between, we show the equivalence of multiset regular language and fuzzy multiset regular language. Finally, we introduce the concept of pumping lemma for fuzzy multiset regular languages, which we use to establish a necessary and sufficient condition for a fuzzy multiset language to be non-cons...

Vagueness is a pervasive feature of natural languages that is challenging semantic theories and theories of language evolution alike. We focus here on the latter, addressing the challenge of how to account for the emergence of vague meanings in signaling game models of language evolution. We suggest that vagueness is a natural property of meaning that evolves when boundedly rational agents repe...

The goal of this paper is to develop a theory of content for vague language. My proposal is based on the following three theses: (1) language-mastery is not rulebased—it involves a certain kind of decision-making; (2) a theory of content is to be thought of instrumentally—it is a tool for making sense of our linguistic practice; and (3) linguistic contents are only locally defined—they are only...

This paper presents first results of a research project whose goal is to develop a pattern language that enhances business software by motivating and engaging elements. The goal of the pattern language is to turn the soft and vague term of “emotions in user interaction design” into constructive design guidance. The patterns are especially tailored for joy-of-use in business applications. The ma...