Conference talks

  • 1975 (November), Chicago, AMS Regional Meeting, "Various Aspects of Abstract Families"

  • 1975 (December), Montreal, CMC Winter Meeting, "Various Aspects of Abstract Families"

  • 1976 (February), Hamilton (Ontario), McMaster Colloquium, "Various Aspects of Abstract Families"

  • 1976 (February), New York, Category Theory Seminar, "Various Aspects of Abstract Families"

  • 1976 (March), St. John's (Newfoundland), Memorial University Colloquium, "Various Aspects of Abstract Families"

  • 1979 (May 23-27), Aspen (Colorado), Symposium on Algebra, "Indexed Categories and Generated Topologies"

  • 1981 (October), Montreal, McGill Topos Meeting, "Indexing by Coalgebras"

  • 1981-1982, Chicago, University of Chicago, series of four lectures on "Indexed Categories"

  • 1982 (July), Isle of Thorns (England), Category Theory Conference, "Families Parametrized by Coalgebras"

  • 1984 (April 26-29), New York, New York Topos Seminar, "Coherence for Indexed Categories"

  • 1984 (July), Murten (Switzerland), Category Theory Conference, "The Tensor and Symmetric Algebra Construction for Comodules"

  • 1985 (December 6-8), Buffalo (New York), Tenth Anniversary Topos Meeting, "Accessible Categories"

  • 1986 (July 20-26), Cambridge (UK), Topos Summer Meeting, "Accessible Categories and Colimits of Topoi"

  • 1986 (October 24-26), Philadelphia, Topos Meeting at University of Pennsylvania, "Self-Dual Accessible Categories"

  • 1986 (December 6-8), Ottawa, CMS Winter Meeting, "Accessible Completions of Categories"

  • 1987 (June 13-20), Boulder (Colorado), AMS Meeting on Logic and Category Theory in Computer Science, "Some Open Problems in, and Applications of, Categorical Model Theory" Slides

  • 1987 (July 26-August 1), Louvain-la-Neuve (Belgium), Category Theory Summer Conference, "Lax Colimits of Accessible Categories"

  • 1988 (May 1-June 1), Louvain-la-Neuve (Belgium), Series of Lectures on Accessible Categories at the Université catholique de Louvain

  • 1988 (August), Prague (Czechoslovakia), Conference on Categorical Topology, "Models of Intuitionistic Sketches in a Topos"

  • 1988 (December), Toronto, CMS Winter Meeting, "Double Limits" ("A Critical Look at Limits in 2-Categories")

  • 1989 (May), Montreal, McGill Category Meeting, "Limits Constructed from Pullbacks"

  • 1989 (July 3-7), Bangor (UK), International Conference on Category Theory, "Double Limits" Slides

  • 1990 (March), Manhattan (Kansas), Regional Meeting of the AMS, "Does Anybody Really Know What a Hopf Algebra Is?"

  • 1990 (July 22-28), Como (Italy), International Conference on Category Theory, "Colimits of Accessible Categories"

  • 1990 (December 7), Montreal, McGill Category Theory Seminar, "Does Anybody Really Know What a Hopf Algebra Is?"

  • 1992 (May 22, 23), Corner Brook (Newfoundland), Atlantic Algebra Conference, "General Associativity and General Composition in Double Categories"

  • 1992 (July), Isle of Thorns (UK), International Conference in Category Theory, "General Associativity and General Composition in Double Categories" Slides

  • 1992, CMS Winter Meeting?, "Tile Orders" Slides

  • 1993 (July), Berkeley (California), Workshop on Universal Algebra and Category Theory (Mathematical Sciences Research Institute), "Accessible Categories" (Invited Talk)

  • 1993 (September), Trieste (Italy), XI Convegno Internazionale di Topologia (11th International Conference on Topology), "Universal Covering Categories" (Invited Talk)

  • 1993 (September 12, 13), Trieste (Italy), 51st Peripatetic Seminar, "Paths in a Category"

  • 1993 (December), Ottawa, CMS Winter Meeting, "Dinatural Numbers" (Invited Talk) Slides

  • 1995 (May), Genoa (Italy), Peripatetic Seminar on Sheaves and Logic, "Dinatural Numbers" Slides

  • 1995 (July 9-15), Halifax (Nova Scotia), CT95 (International Category Theory Conference), "Accessible Categories" Slides

  • 1996 (April 12-14), Toronto, Spring Conference on Categories (York University), "Representables for Double Categories" (Invited Address)

  • 1997 (July 13-19), Vancouver, CT 97 (International Category Theory Conference), "Representables for Double Categories" Slides

  • 1997 (September 26-28), Montreal, AMS Meeting, "On the Cardinality of Functors"

  • 1997 (December 5), Montreal, McGill University, "The Work of Jim Lambek in Category Theory" Slides

  • 1998 (June 12-16), Saint John (NB), CMS Summer Meeting, "Functorial Finite Differences"

  • 1999 (July 19-24), Coimbra (Portugal), CT 99, "Filtered Double Categories" Slides (Incomplete)

  • 2000 (September 22-24), Toronto, AMS Meeting, "Free Double Categories and the Word Problem for Groups" Slides

  • 2000 (October), "Orthogonal Adjoints in Double Categories" Slides

  • 2002 (September 23-28), Toronto (Fields Institute: Workshop on Categorical Structures for Descent and Galois Theory, Hopf Algebras and Semiabellian Categories), "The Topos of 'Cocommutative Coalgebras'"

  • 2002 (October 18-20), Sackville (NB), APICS Meeting at Mount Allison, "Comonoids in the Category of Relations"

  • 2004 (June 11-15), Halifax (NS), CMS Summer Meeting at Dalhousie, "The Most General Distributive Law in the World" Slides

  • 2006 (June 25-July 1), White Point (NS), CT 2006, "Spans for 2-Categories" Slides

  • 2007 (December 8-10), Western University (London, Ontario), CMS Winter Meeting, "Kan Extensions for Double Categories" Slides

  • 2008 (June 22-28), Calais (France), CT 2008 (Université du Littoral Côte d'Opale), "Spans for 2-Categories and Comma Objects" Slides

  • 2009 (June 18-20), Montreal, Centre de recherches mathématiques (Models, Logics and Higher-Dimensional Categories: A tribute to the work of Mihaly Makkai), "First Order Theories as Double Lawvere Theories" Slides

  • 2009 (June 29-July 4), Cape Town (South Africa), CT 2009, "First Order Theories as Double Lawvere Theories" Slides

  • 2010 (March), Washington (DC), Meeting of Association for Symbolic Logic, "Double Categories of Models" Slides

  • 2010 (June 2-6), Fredericton (NB), CMS Summer Meeting, "Mealy Morphisms for Tensor Categories" Slides

  • 2011 (June 2-5), Edmonton (AB), CMS Summer Meeting, "Lax Presheaves for Double Categories" Slides

  • 2011 (July 17-23), Vancouver (BC), CT 2011, "Yoneda Theory for Double Categories" (Invited Talk) Slides

  • 2011 (October 22, 23), Ottawa, Category Theory 'Octoberfest', "Composition of Modules for Lax Functors" Slides

  • 2012 (June 14-17), Workshop on Foundational Methods in Computer Science (FMCS) (Halifax, Nova Scotia), "Colimits and Profunctors" Slides

  • 2012 (July 9-13), Coimbra (Portugal), Workshop on Category Theory in Honour of George Janelidze on the occasion of his 60th birthday, "An Application of Profunctors in the Study of Colimits" Slides

  • 2012 (October 27, 28), Montreal, Category Theory 'Octoberfest' at Concordia University (Montreal), "Multivalued Functors" Slides

  • 2013 (June), Halifax, Session in honour of Luzius Grunenfelder, "Comonoids in Rel" Slides

  • 2013 (June), Halifax, CMS Summer Meeting, "The 'Triple Category' of Bicategories" Slides

  • 2014 (June 29-July 5), Cambridge (UK), CT 2014, "Intercategories" Slides

  • 2014 (October), Halifax (NS), AMS Meeting, "Examples of Intercategories" Slides

  • 2014 (November 7), In memory of Dietmar Schumacher (Acadia University, Wolfville, Nova Scotia), "What's category theory, anyway?" Slides

  • 2015 (June 14-19), Aveiro (Portugal), CT 2015, "Skolem Relations and Profunctors" Slides

  • 2015 (October), Ottawa, Category Theory 'Octoberfest', "Superspans" Slides

  • 2016 (August 7-13), Halifax (NS), CT 2016, "Isotropic Intercategories" Slides

  • 2017 (June 16-22), Vancouver, CT 2017, "Hypercategories" Slides

  • 2018 (May 31), Sackville, NB, FMCS, "Double Categories: The best thing since slice categories" Slides

  • 2018 (June 1), Sackville, NB, FMCS, "Seeing Double" Slides

  • 2018 (July 13), Azores, Portugal, CT 2018, "A double category take on restriction categories" Slides

  • 2019 (July 10), Edinburgh, Scotland, CT 2019, "Retrocells" Slides

  • 2020 (October 8), MIT Categories Seminar, "Retrocells Redux" Slides

  • 2021 (February 10), UNAM Seminar,Mexico, "A case study in double categories" Slides

  • 2021 (November 18), Casa Abierta, Mexico, "The Double Theory of Monads" Slides

  • 2022 (October 29), Octoberfest, Ottawa, "The Double Category of Abelian Groups" Slides

  • 2022 (November 28), Virtual Double Category Workshop, "Some things about double categories" Slides

  • 2022 (December 7), New York Category Seminar, New York, "The horizontal/vertical synergy of double categories" Slides

  • 2024 (January 11), Topos Institute Colloquium, "The Functorial Difference Operator" Slides

  • 2024 (June 27), Santiago de Compostela, Spain, "The difference calculus for functors on presheaves" Slides


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