The paper discusses the problem of determinising finite-state automata containing large numbers of ǫ-moves. Experiments with finite-state approximations of natural language grammars often give rise to very large automata with a very large number of ǫ-moves. The paper identifies three subset construction algorithms which treat ǫ-moves. A number of experiments has been performed which indicate th...

We study determinization of weighted finite-state automata (WFAs), which has important applications in automatic speech recognition (ASR). We provide the first polynomial-time algorithm to test for the twins property, which determines if a WFA admits a deterministic equivalent. We also provide a rigorous analysis of a determinization algorithm of Mohri, with tight bounds for acyclic WFAs. Given...

This paper is a survey on logical aspects of nite automata Central points are the connection between nite automata and monadic second order logic the Ehrenfeucht Fra ss e technique in the context of formal language theory nite automata on words and their determinization and a self contained proof of the Rabin Tree Theorem Sections and contain material presented in a lecture series to the Final ...

Component interfaces are the essence of modular program analysis. In this work, a component interface documents correct sequences of invocations to the component’s public methods. We present an automated framework that extracts finite safe, permissive, and minimal interfaces, from potentially infinite software components. Our proposed framework uses the L* automata-learning algorithm to learn f...

Coalgebra offers a unified theory of state based systems, including infinite streams, labelled transition systems and deterministic automata. In this paper, we use the coalgebraic view on systems to derive, in a uniform way, abstract procedures for checking behavioural equivalence in coalgebras, which perform (a combination of) minimization and determinization. First, we show that for coalgebra...

In the paper, we generalize an algorithm and some related results by Mohri [25] for determinization of weighted finite automata (WFA) over the tropical semiring. We present the underlying mathematical concepts of his algorithm in a precise way for arbitrary semirings. We define a class of semirings in which we can show that the twins property is sufficient for the termination of the algorithm. ...

This paper discusses a case study of the board game of Scotland Yard from a computational perspective. Interestingly, Scotland Yard is a genuine “playgame” with imperfect information. For reasons not completely clear to me, games with imperfect information have escaped the interest of researchers in Algorithmic combinatorial gametheory. I show by means of a powerset argument, that Scotland Yard...

Complete lattices are considered with suitable families of lattice morphisms that provide a structure (L,Φ), useful to characterize ground categories of L-sets by means of powerset operators associated to morphisms of these categories. The construction of ground categories and powerset operators presented here extends and unifies most approaches previously considered, allowing the use of noncri...

We give a category-theoretic formulation of Engeler-style models for the untyped λ-calculus. In order to do so, we exhibit an equivalence between distributive laws and extensions of one monad to the Kleisli category of another and explore the example of an arbitrary commutative monad together with the monad for commutative monoids. On Set as base category, the latter is the finite multiset mona...

We introduce basic notions and results about relation liftings on categories enriched in a commutative quantale. We derive two necessary and sufficient conditions for a 2-functor T to admit a functorial relation lifting: one is the existence of a distributive law of T over the “powerset monad” on categories, one is the preservation by T of “exactness” of certain squares. Both characterisations ...