Discrete Mathematics..

c­ IOP Publishing Ltd 2002All rights reserved. No part of this publication may be reproduced, storedin a retrieval system or transmitted in any form or by any means, electronic,mechanical, photocopying, recording or otherwise, without the prior permissionof the publisher. Multiple copying is permitted in accordance with the termsof licences issued by the Copyright Licensing Agency under the terms of itsagreement with the Committee of Vice-Chancellors and Principals.British Library Cataloguing-in-Publication DataA catalogue record for this book is available from the British Library.ISBN 0 7503 0652 1Library of Congress Cataloging-in-Publication Data are availableFirst Edition published 1992First Edition reprinted 1996, 1997, 1999Commissioning Editor: James RevillProduction Editor: Simon LaurensonProduction Control: Sarah PlentyCover Design: Frédérique SwistMarketing Executive: Laura SerratricePublished by Institute of Physics Publishing, wholly owned by The Institute ofPhysics, LondonInstitute of Physics Publishing, Dirac House, Temple Back, Bristol BS1 6BE, UKUS Office: Institute of Physics Publishing, The Public Ledger Building, Suite1035, 150 South Independence Mall West, Philadelphia, PA 19106, USATypeset in L A TEX2 by Text 2 Text, Torquay, DevonPrinted in the UK by MPG Books Ltd, Bodmin, Cornwall