CAUTION: The Sender of this email is not from within Dalhousie. Please mark your calendars for our seminar Friday next week! Reiko On 15/03/2021, 09:36, "GReTA seminar organisers" <greta@irif.fr> wrote: Dear colleagues, It is our great pleasure to invite you to the next seminar of the “GReTA - Graph Transformation Theory and Applications” series: Friday, March 26, 15:00 CET “Formal Graph Language Theory & Fusion Grammars”, H.-J. Kreowski & A.F. Lye (abstracts: see attached) Please refer to http://www.irif.fr/~greta<https://eur03.safelinks.protection.outlook.com/?url=http:%2F%2Fwww.irif.fr%2F~greta&data=04%7C01%7Crh122%40leicester.ac.uk%7Cb833faff9cca48b8a4fa08d8e795bf16%7Caebecd6a31d44b0195ce8274afe853d9%7C0%7C0%7C637513977629005205%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=skN7PVjbuOJ8gO0Fw2wexXk1BBaMPGJXy%2BPQbLG4ntM%3D&reserved=0> for further information on how to register for this Zoom meeting, or alternatively on how to attend the meeting via a YouTube live stream! The GReTA 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 scheduled twice a month (cf. https://www.irif.fr/~greta/#talks<https://eur03.safelinks.protection.outlook.com/?url=https:%2F%2Fwww.irif.fr%2F~greta%2F%23talks&data=04%7C01%7Crh122%40leicester.ac.uk%7Cb833faff9cca48b8a4fa08d8e795bf16%7Caebecd6a31d44b0195ce8274afe853d9%7C0%7C0%7C637513977629015194%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=bvgx%2FMfKapPDuAKFrQzgmoEY%2BINpyn0bokkSNSx3i1I%3D&reserved=0> for a list of upcoming events). With best regards, Nicolas Behr, Jean Krivine and Reiko Heckel (GReTA organisers) ___________________________________________________ Date and time: Friday, March 26, 15:00 CET Title: Formal Graph Language Theory & Fusion Grammars Speakers: Hans-Jörg Kreowski & Aaron Frederick Lye (University of Bremen, Germany) Abstract: In the first part of the presentation, some aspects of formal graph language theory are discussed. A few variants of graph grammars were introduced in the early 1970s as generalizations of Chomsky grammars. This first step into a formal graph language theory was further developed by the investigation of edge and hyperedge replacement on one hand and on some variants of node replacement on the other hand starting in the late 1970s. Since then, a good number of structural and decidability properties were proved. In particular, it turned out that hyperedge replacement grammars behave to a large degree in a context-free manner. In the second part of the presentation, the novel approach of fusion grammars is surveyed. A fusion grammar is a hypergraph grammar which provides a start hypergraph of small connected components. To derive hypergraphs, connected components can be copied multiple times and can be fused by the application of fusion rules (where such an application removes two complementary hyperedges and merges their attachment vertices). The generated hypergraph language contains all terminal connected components of derived hypergraphs. The main results for various kinds of fusion grammars concern their generative power. Zoom registration link: https://zoom.us/meeting/register/tJIrdO2prjsqG9MrJ5ahIxtg3vbAkwLqIXfO<https://eur03.safelinks.protection.outlook.com/?url=https%3A%2F%2Fzoom.us%2Fmeeting%2Fregister%2FtJIrdO2prjsqG9MrJ5ahIxtg3vbAkwLqIXfO&data=04%7C01%7Crh122%40leicester.ac.uk%7Cb833faff9cca48b8a4fa08d8e795bf16%7Caebecd6a31d44b0195ce8274afe853d9%7C0%7C0%7C637513977629015194%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=bNIy%2FGHg3DoWiZZDaNRPaTBO4FQO0ryfKgBmdfqOJfA%3D&reserved=0> Link to YouTube live stream: https://youtu.be/142aNpKPv04<https://eur03.safelinks.protection.outlook.com/?url=https%3A%2F%2Fyoutu.be%2F142aNpKPv04&data=04%7C01%7Crh122%40leicester.ac.uk%7Cb833faff9cca48b8a4fa08d8e795bf16%7Caebecd6a31d44b0195ce8274afe853d9%7C0%7C0%7C637513977629025193%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=wOKWmGOiQeQHdPrN%2B8jyZIB7%2B2HwqoZ3ccRhQBkDCaQ%3D&reserved=0> ___________________________________________________ ---------------------------------------------------------------------------- GReTA - Graph TRansformation Theory and Applications International Online Seminar Series ---------------------------------------------------------------------------- Contact: greta@irif.fr<mailto:greta@irif.fr> Webpage: www.irif.fr/~greta<https://eur03.safelinks.protection.outlook.com/?url=http:%2F%2Fwww.irif.fr%2F~greta&data=04%7C01%7Crh122%40leicester.ac.uk%7Cb833faff9cca48b8a4fa08d8e795bf16%7Caebecd6a31d44b0195ce8274afe853d9%7C0%7C0%7C637513977629974657%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=1BLd0u51q5pwWxMObUXEPgDJPrlc3t9kzaVcG%2Bmru6E%3D&reserved=0> YouTube: https://www.youtube.com/channel/UC6j-G6oPmkqCgOx6UQOUhSQ<https://eur03.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.youtube.com%2Fchannel%2FUC6j-G6oPmkqCgOx6UQOUhSQ&data=04%7C01%7Crh122%40leicester.ac.uk%7Cb833faff9cca48b8a4fa08d8e795bf16%7Caebecd6a31d44b0195ce8274afe853d9%7C0%7C0%7C637513977629974657%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=%2Bjet16blwv1%2FG6ePVOf%2BOx5Rms7Ep%2Fe4lpOHrThSJKk%3D&reserved=0> Twitter: https://twitter.com/GReTAseminars<https://eur03.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftwitter.com%2FGReTAseminars&data=04%7C01%7Crh122%40leicester.ac.uk%7Cb833faff9cca48b8a4fa08d8e795bf16%7Caebecd6a31d44b0195ce8274afe853d9%7C0%7C0%7C637513977629984647%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=WhTQtAvNup3RrCpU9be3S4gbcABYjsvmKVRcx45Xg9Q%3D&reserved=0> [For admin and other information see: http://www.mta.ca/~cat-dist/ ]