{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,19]],"date-time":"2026-01-19T08:47:19Z","timestamp":1768812439646,"version":"3.49.0"},"reference-count":12,"publisher":"World Scientific Pub Co Pte Lt","issue":"04","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Int. J. Found. Comput. Sci."],"published-print":{"date-parts":[[2011,6]]},"abstract":"<jats:p> We present efficient algorithms for testing the finite, polynomial, and exponential ambiguity of finite automata with \u03b5-transitions. We give an algorithm for testing the exponential ambiguity of an automaton A in time [Formula: see text], and finite or polynomial ambiguity in time [Formula: see text], where |A|<jats:sub>E<\/jats:sub> denotes the number of transitions of A. These complexities significantly improve over the previous best complexities given for the same problem. Furthermore, the algorithms presented are simple and based on a general algorithm for the composition or intersection of automata. Additionally, we give an algorithm to determine in time [Formula: see text] the degree of polynomial ambiguity of a polynomially ambiguous automaton A and present an application of our algorithms to an approximate computation of the entropy of a probabilistic automaton. <\/jats:p><jats:p> We also study the double-tape ambiguity of finite-state transducers. We show that the general problem is undecidable and that it is NP-hard for acyclic transducers. We present a specific analysis of the double-tape ambiguity of transducers with bounded delay. In particular, we give a characterization of double-tape ambiguity for synchronized transducers with zero delay that can be tested in quadratic time and give an algorithm for testing the double-tape ambiguity of transducers with bounded delay. <\/jats:p>","DOI":"10.1142\/s0129054111008477","type":"journal-article","created":{"date-parts":[[2011,6,10]],"date-time":"2011-06-10T08:52:34Z","timestamp":1307695954000},"page":"883-904","source":"Crossref","is-referenced-by-count":13,"title":["GENERAL ALGORITHMS FOR TESTING THE AMBIGUITY OF FINITE AUTOMATA AND THE DOUBLE-TAPE AMBIGUITY OF FINITE-STATE TRANSDUCERS"],"prefix":"10.1142","volume":"22","author":[{"given":"CYRIL","family":"ALLAUZEN","sequence":"first","affiliation":[{"name":"Google Research, 76 Ninth Avenue, New York, NY 10011, US"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"MEHRYAR","family":"MOHRI","sequence":"additional","affiliation":[{"name":"Courant Institute of Mathematical Sciences, 251 Mercer Street, New York, NY 10012, US"},{"name":"Google Research, 76 Ninth Avenue, New York, NY 10011, US"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"ASHISH","family":"RASTOGI","sequence":"additional","affiliation":[{"name":"Goldman, Sachs &amp; Co., 200 West Street, New York, NY 10282, US"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"219","published-online":{"date-parts":[[2011,11,20]]},"reference":[{"key":"rf1","first-page":"117","volume":"8","author":"Allauzen Cyril","journal-title":"Journal of Automata, Languages and Combinatorics"},{"key":"rf3","doi-asserted-by":"publisher","DOI":"10.1016\/0304-3975(88)90012-6"},{"key":"rf4","doi-asserted-by":"publisher","DOI":"10.1142\/S0129054108005644"},{"key":"rf5","doi-asserted-by":"publisher","DOI":"10.1002\/0471200611"},{"key":"rf6","volume-title":"Computers and Intractability: A Guide to the Theory of NP-Completeness","author":"Garey Michael R.","year":"1990"},{"key":"rf8","doi-asserted-by":"publisher","DOI":"10.1016\/0304-3975(77)90006-8"},{"key":"rf10","doi-asserted-by":"publisher","DOI":"10.1016\/0304-3975(77)90001-9"},{"key":"rf12","doi-asserted-by":"publisher","DOI":"10.1142\/S0129054103002114"},{"key":"rf14","volume-title":"Finite State Language Processing","author":"Pereira Fernando","year":"1997"},{"key":"rf15","doi-asserted-by":"publisher","DOI":"10.1090\/S0002-9904-1946-08555-9"},{"key":"rf16","doi-asserted-by":"publisher","DOI":"10.1137\/0218083"},{"key":"rf20","doi-asserted-by":"publisher","DOI":"10.1016\/0304-3975(91)90381-B"}],"container-title":["International Journal of Foundations of Computer Science"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.worldscientific.com\/doi\/pdf\/10.1142\/S0129054111008477","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2019,8,6]],"date-time":"2019-08-06T20:33:23Z","timestamp":1565123603000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.worldscientific.com\/doi\/abs\/10.1142\/S0129054111008477"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2011,6]]},"references-count":12,"journal-issue":{"issue":"04","published-online":{"date-parts":[[2011,11,20]]},"published-print":{"date-parts":[[2011,6]]}},"alternative-id":["10.1142\/S0129054111008477"],"URL":"https:\/\/doi.org\/10.1142\/s0129054111008477","relation":{},"ISSN":["0129-0541","1793-6373"],"issn-type":[{"value":"0129-0541","type":"print"},{"value":"1793-6373","type":"electronic"}],"subject":[],"published":{"date-parts":[[2011,6]]}}}