Retraction Note for "PDL Has Interpolation"Author(s): Tomasz KowalskiSource: The Journal of Symbolic Logic, Vol. 69, No. 3 (Sep., 2004), p. 935Published by: Association for Symbolic LogicStable URL: http://www.jstor.org/stable/30041768 .

Accessed: 16/06/2014 06:30

Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at .http://www.jstor.org/page/info/about/policies/terms.jsp

.JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range ofcontent in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new formsof scholarship. For more information about JSTOR, please contact support@jstor.org.

.

Association for Symbolic Logic is collaborating with JSTOR to digitize, preserve and extend access to TheJournal of Symbolic Logic.

http://www.jstor.org

This content downloaded from 185.2.32.106 on Mon, 16 Jun 2014 06:30:37 AMAll use subject to JSTOR Terms and Conditions

THE JOURNAL OF SYMBOLIC LOGIC

Volume 69, Number 3, Sept. 2004

RETRACTION NOTE FOR "PDL HAS INTERPOLATION"

TOMASZ KOWALSKI

In this journal I published a paper [1] entitled "PDL has interpolation" purporting to prove what the title announced. It has been pointed out to me by Yde Venema that my argument contains a serious error. As I have not been able to correct it, the problem of interpolation for Propositional Dynamic Logic is still open.

REFERENCES

[1] TOMASZ KOWALSKI, PDL has interpolation, this JOURNAL, vol. 67 (2003), no. 3, pp. 933-946.

AUTOMATED REASONING GROUP COMPUTER SCIENCES LABORATORY

RESEARCH SCHOOL OF INFORMATION SCIENCES AND ENGINEERING AUSTRALIAN NATIONAL UNIVERSITY

CANBERRA, ACT 0200, AUSTRALIA E-mail: Tomasz.Kowalski@anu.edu.au

Received May 24, 2004.

+ 2004, Association for Symbolic Logic 0022-4812/04/6903-0020/$1.10

935

This content downloaded from 185.2.32.106 on Mon, 16 Jun 2014 06:30:37 AMAll use subject to JSTOR Terms and Conditions