GReTA seminar #32: "PBPO+: A Unifiying Theory for Quasitoposes"
Channel: GReTA Seminar
Date: 20/05/2022

Speaker:

Roy Overbeek (Department of Computer Science, Vrije Universiteit, Amsterdam, Netherlands)


Abstract:

Last year we proposed PBPO+, which extends the Pullback-Pushout (PBPO) approach by Corradini et al. with strong matching. Now, we have proved that in the setting of quasitoposes (and assuming regular monic matching), PBPO+ can define all rewrite relations definable by PBPO, AGREE, SqPO and DPO -- as well as additional ones. In this sense, PBPO+ can be considered a unifying theory in this setting. In this talk we reflect on the notion of a quasitopos, and explain how from its many nice properties our result can be obtained. This is joint work with Jörg Endrullis and Aloïs Rosset.


About the GReTA seminars:

The GReTA – Graph TRansformation Theory and Applications virtual seminar series aims to serve as a platform for the international graph rewriting community, to promote recent developments and trends in the field, and to permit a regular networking and interaction between members of this community. Seminars are held twice a month in the form of Zoom sessions (some of which will be live-streamed to YouTube). Please refer to http://www.irif.fr/~greta for further details (including information on how to register for participating in the Zoom meetings).