Technical Report: DCC-2011-10

DesCo: a Web Based Information System for Descriptional Complexity Results

Nelma Moreira, Davide Nabais, Rogério Reis

CMUP & DCC-FC, Universidade do Porto e-mail: {nam,dnabais,rvr}

August 2011


Recently the descriptional complexity of formal languages has been extensively researched. One of the most studied complexity measures for regular languages is the number of states of its minimal automaton (state complexity of the language). Other measures can be related to other structural components and other models of computation. The complexity of a language operation is the complexity of the resulting language seen as a function of the complexities of the operation arguments. This proliferous research gave origin to a multitude of results scattered over more than 200 articles, with the inevitable lack of unified terminology and notation. This makes it very difficult to a interested researcher to have a global perspective of this field and realize what is the current coverage achieved in order to know where to allocate more research efforts. In this paper we present a first step towards the development of a Web based information system were descriptional complexity results can be structurally introduced, queried, and viewed. This tool will also interact with symbolic manipulation systems in order to obtain examples and perform experimental tests. Moreover the system enables the user to easily customize the database queries in order to get novel views over the existing results and respective bounds. Here we describe the main components of the database, the technologies used and the Web user interface.