June 19, 2025 (online) "Counting congruences: the largest and beyond for lattices, and the maximum for congruence-distributive algebras". Presented online at the 17th International Summer-School Conference ``Problems Allied to Universal Algebra and Model Theory'', Novosibirsk, handout.pdf .

July 8, 2024 (online) "Generating quasiorder lattices and some other lattices by few elements". Presented online at the 16th International Summer-School Conference ``Problems Allied to Universal Algebra and Model Theory'', Novosibirsk slides.pdf = tinyurl.com/czg-ns2024 , handout.pdf = https://tinyurl.com/czg2024gq, abstract.pdf, and the related paper.pdf .

June 21, 2023 (online) Generating quasiorder lattices and some other lattices by few elements. Presented online at the 15th International Summer-School Conference ``Problems Allied to Universal Algebra and Model Theory'', Novosibirsk - Erlagol, slides.pdf.

April 5, 2023 (online), Dept. Algebra, Szeged: " Generating the principal filters of quasiorder lattices and, in connection with it, a way from Zádori's method to a secret key cryptography " (" Kvázirendezés-hálók nagy főfiltereinek generálása és ezzel kapcsolatban: út a Zádori-módszertől egy titkosírásig "), preliminary abstract (or here) , slides.pdf..

September 1-7, 2019, SSAOS-57 (57th Summer School on General Algebra and Ordered sets), Karolinka, Czech Republic: "Eighty-three sublattices and planarity", slides.pdf, handout-pdf , &, related paper.pdf and related-paper-extended-version.pdf

September 2-7, 2018, SSAOS-56 (56th Summer School on General Algebra and Ordered sets), Spindleruv Mlyn, Czech Republic: "Lattice with many congruences are planar", slides.pdf, handout-pdf , related paper.pdf

September 3-8, 2017, SSAOS-55 (55th Summer School on General Algebra and Ordered sets), Novy Smokovec, Slovakia: "Cometic functors for principal lattice congruences", slides.pdf, handout-pdf , related paper.pdf & errata

June 14-18, 2017, Novi Sad (AAA94 and 5th Novi Sad Algebraic Conference) "From weak congruence lattices to circles and an online game", slides-of-talk.pdf

November 30, 2016, Bolyai Institute (Szeged), jointly with János Kincses: "Representing finite convex geometries in lattice theoretical and geometrical ways"; slides-of-talk.pdf

November 17, 2016, Bolyai Intézet (Szeged), "Kongruenciahálóktól a körök lokálisan konvex geometriájáig" (a Szőkefalvi-Nagy Béla érem átvétele alkalmából), slides-of talk.pdf

October 27, 2016, Keréjártó Szeminíárium, Szeged: "Miért horpasztottuk be a köröket? pdf

September 3-9, 2016, 54th Summer School on General Algebra and Ordered Sets (Trojanovice, Czech Republic), "Lattices embeddable in three-generated lattices", slides of talk, related paper.

February 24, 2016, Budapest, "Történetek kongruenciahálókról" ("Schmidt E. Tamás 80" tudományos nap), slides of talk .

August 29--September 4, 2015, SSAOS-53 (53rd Summer School on General Algebra and Ordered sets), Srni, Czech Republic, "Geometric constructibility of cyclic polygons and a limit theorem" (with Ádám Kunos), slides of talk, related paper.

June 4-7, 2015, AAA90 Workshop on General Algebra and Ordered Sets (Novi Sad, Serbia); "The asymptotic number of planar, slim, semimodular lattice diagrams", slides of talk , related paper .

September 6-12, 2014, 52nd Summer School on General Algebra and Ordered Sets (Stara Lesna, Slovakia), "Posets of principal lattice congruences", talk, related paper .

September 1-7, 2013: 51st Summer School on General Algebra and Ordered Sets (Trojanovice, Czech Republic), "Quasiplanar poset diagrams", talk, related paper.

June 4-9, 2013: Novi Sad, "Coordinatization of join-distributive lattices", slides, related papers 1 and 2

May 30 - June, 2013: AAA86, Olomouc; no talk.

February 18, 2013, Rényi Institute, Budapest, "Sovány féligmoduláris hálókkal kapcsolatos struktúrák" (Structures related with slim semimodular lattices),slides

September 2-7, 2012, 50th Summer School on General Algebra and Ordered Sets, (Novy Smokovec, Slovakia) "Planar semimodular lattices: structure and diagrams" (with George Grätzer), 2 * 50 minutes, slides, printed (and distributed) version.

June 21-25, 2012, Conference on Universal Algebra and Lattice Theory, Szeged:
(1) Tolerance factorable varieties and four ways Bela Csakany influenced their study (with Ivan Chajda and Radomir Halas) abstract, talk, related papers [*} and [*] ;
(2) Emil W. Kiss (with G. Czédli): Congruence preimages of tolerances and four ways Béla Csákány influenced their study, abstract, talk, related paper [*];
(3) T. Dékány, L. Ozsvárt, N. Szakács, B. Udvari (with G. Czédli): On the number of slim semimodular lattices, abstract, talk, related papers: [*], [*]

June 17-20, 2012, Workshop "Algebra Across Borders II", Szeged: "An overview of planar semimodular lattices", abstract .

June 7-10, 2012, AAA84 Workshop on General Algebra, Dresden, Germany: Semimodular lattices determined by permutations (with E. T. Schmidt), abstract, talk, related papers [*], [*]

March 15-18, 2012, AAA83, Novi Sad: The asymptotic number of ways to intersect two composition series (with L. Ozsvárt, E.T. Schmidt, B. Udvari). Lecture, abstract, related papers [*], [**]

September 3-9, 2011, SSAOS-2011, Svratka, Czecz Republic: "Slim semimodular lattices. II. A description by patchwork systems". Talk.pdf, related paper: [*.pdf]

June 6-10, 2011, Kraków, Poland (conference): "The visual structure of planar semimodular lattices" (with E.T. Schmidt). Talk.pdf, abstract, related paper [97].

February 20-20, 2011, Szeged, Symposium on Applications of Lattice Theory: "The visual structure of planar semimodular lattices and an application" (with E.T. Schmidt). Related papers: [pdf] and [95]

September 4-10, 2010, Malenovice (Beskydy Mountains), Czech Republic: "A locomotive that strengthens the Jordan-Hölder theorem". Talk.pdf. Related papers: [95]

June 21-25, 2010, Prague, Jardafest (J. Jezek 65): "The Jordan-Hölder theorem with uniqueness for groups and semimodular lattices". Abstract and talk.pdf. Related paper: [95]

June 1-6, 2010, AAA80, Bedlewo, Poland: "Sums and tolerances of lattices" (with G. Grätzer) Abstractf and talk.pdf. Related papers: [12], [87], [94]

April 12 and 15, 2010, Budapest Rényi Inst./ Szeged Bolyai Inst.: "The Jordan-Hölder theorem with uniqueness". (with E.T. Schmidt). Related paper: [95]

February 12-14, 2010, AAA79, Olomouc: "Some recent results on semimodular lattices" (with E.T. Schmidt) (pdf file). (plenary) Related papers: [77] , [78] , [80] , [84], [91], [?] and [93]

August 17-21, 2009, Novi Sad Algebraic Conference (3rd): "Modular fractal lattices and von Neumann frames". (pdf) Related papers: [73], [74], [88].

June 10-15, 2009, Bern, AAA78 Workshop on General Algebra: "On the height of order ideals" (with M. Maróti) (pdf). Related paper: [86]

May 22-25, 2008, Linz, AAA76 Workshop on General Algebra: "On the variety generated by planar modular lattices" (with M. Maróti) (pdf) Related paper: [85]

April 9 and October 20, 2008, Szeged / Budapest Rényi Institute: "On Frankl's conjecture by means of lattices"  (with M. Maróti and E.T. Schmidt) (pdf in Hungarian). Papers:[78], [80], [84] 

November 2-4, 2007, AAA75 Darmstadt (Rudolf Wille is 70): "Stronger association rules in algebra" (plenary) (pdf). Related papers: [70], [72], [76], [79], [90]

September 7, 2007, Tale (Slovakia) , The 45th Summer School on General Algebra and Oredered Sets (Tibor Katrinak is 70): "Fractal lattices I". (pdf file); Related paper: [73]

May 10, 2007, Szeged Bolyai Inst.: "Definiálhatta volna-e Neumann János a folytonos geometriákat jobban?" (pdf). Related papers: [73], [74]

March 19 and 23, 2007 Budapest Rényi Inst. and Novi Sad March: "Fractal lattices and what they generate" (pdf). Related papers: [73], [74]

June 6-9, 2006, Budapest Grätzer-Schmidt 70 Conference: "An associtation rule motivated by Grätzer and Schmidt" (plenary) (pdf). Related papers: [70], [72]

February 24, 2016, Budapest, "Történetek kongruenciahálókról" ("Schmidt E. Tamás 80" tudományos nap),slides of talk .

September 2-7, 2012, 50th Summer School on General Algebra and Ordered Sets, "Planar semimodular lattices: structure and diagrams" (with George Grätzer), 2 * 50 minutes,slides, printed (and distributed) version.

February 12-14, 2010, AAA79, Olomouc: "Some recent results on semimodular lattices" (with E.T. Schmidt) (pdf file). (plenary) My related papers: [77] , [78] , [80] , [84] , [?] and [93]

November 2-4, 2007, AAA75 Darmstadt (Rudolf Wille is 70): "Stronger association rules in algebra" (plenary) (pdf file). Related papers: [70], [72], [76], [79], [90]

June 6-9, 2006, Budapest Grätzer-Schmidt 70 Conference: "An associtation rule motivated by Grätzer and Schmidt" (plenary) (pdf file). Related papers: [70], [72]