- Negation on the neo-Australian Plan, Logica 2019, 33rd International Symposium, Hejnice Monastery, Czech Repubic, June 24-28, (2019).
- Dualising on Implicit and Explicit Knowledge II, Prague Workshop on Non--Classical Epistemic Logics, Departments of Logic, Institute of Philosophy ASCR and Faculty of Arts, Charles University, Prague, Czech Republic, June 22-23, (2013).
- Positive Introspection and Neo--Infinitism, Logica 2013, 26th International Symposium, Hejnice Monastary, Czech Republic, June 17-21 (2013).
- Attitudes and Duals, LiRA Seminar, Institute for Logic, Language, and Computation (ILLC), Amsterdam, The Netherlands, May 14, (2013).
- Hume's Principle and Ontological Neutrality: a neo--neo--Fregean Proposal, Munich Centre for Mathematical Philosophy, University of Munich, January 17, (2013).
- Epistemic Duals and Explicit Considerations, Logica 2012, 25th International Symposium, Hejnice Monastery, Czech Repubic, June 18-22, (2012).
- Dualising on Implicit and Explicit Knowledge, Prague Workshop on Non–classical epistemic logics, Departments of Logic, Institute of Philosophy ASCR and Faculty of Arts, Charles University, Prague, Czech Republic, June 14-16, (2012).
- Epistemic Operations, Fourth Workshop on the Philosophy of Information, University of Hertfordshire, May 10 - 11, (2012).
- Action-Typing, Logic Group Seminar, National Technical University of Athens, April 26, (2012).
- Metaphysical Safety: From Platonism to Noneism via Hume's Principle, Departmental Colloquia, Department of Philosophy, University of Nevada Las Vegas, March 23, (2012).
- Modelling Epistemic Actions...Again...., Roots of Deduction Workshop, Faculty of Philosophy, University of Groningen, The Netherlands, November 29 - 30, (2011).
- Logical Hyperintensionality: From Consequences to Actions, CLMPS2011,
14th Congress on Logic, Methodology, and Philosophy of Science, Nancy, France, July 19 - 26, (2011).
- Unifying Relevant, Epistemic, and Justification Logics, Prague
Workshop on Epistemic Logics, Departments of Logic, Institute of Philosophy ASCR and Faculty of Arts, Charles University, Prague, Czech Republic, June 17-17, (2011).
- Analyticity and Existence, Logica 2011,
24th International Symposium, Hejnice Monastery, Czech Repubic, June 21-25, (2011).
- Incompatibility, Brown Bag Seminar, Faculty of Philosophy, University of Groningen, The Netherlands, April 19, (2011).
- Epistemic Actions for Non-ideal Agents,
20th workshop on Games, Logic, Language, and Computation:
Epistemic Actions for Non-Ideal Agents, Institute for Logic, Language, and Computation
(ILLC), University of Amsterdam, The Netherlands, February 22, (2011).
- Modelling Epistemic Actions, LIRa Seminar: Special session on substructural logics, information, and interaction, Institute for Logic, Languae, and Computation (ILLC), University of Amsterdam, The Netherlands, January 24, (2011).
- What is a Deduction? Integrating Logical, Psychological, and Philosophical Perspectives [logic component],with Catarina Dutilh [philosophical component], and Andy Fugard and Niki Pfeifer [psychological component], 18th meeting of the European Society for Philosophy and Psychology (ESPP), Bochum and Essen, Germany, August 25-28 (2010).
- Non-symmetric (In)Compatibility Relations and Non-Commuting Types, Logica 2010: 24th International Symposium, Hejnice Monastery, Czech Repubic, June 21-25, (2010).
- Structured Reasoning as Database Constraints, Second International Workshop on the Philosophy of Information, Anakara, Turkey, May 20-21, (2010).
- Permuting Nonassociating Lambek Calculus and Cognitive Grammars, UNILOG III, Lisbon, Portugal, April 22-25, (2010).
- Negation as Test-Failure in DPL and Negation as Process Exclusion in Categorical Grammar, UNILOG III, Lisbon, Portugal, April 22-25, (2010).
- (In)Compatibility Relations, Operational Semantics, and Test-Failure, DIP-Colloquium, Institute for Logic, Language, and Computation (ILLC), University of Amsterdam, The Netherlands, March 12, (2010).
- Lexicons and Databases, Agents and Systems, The Data Explosion Seminar Series, Centrum Wiskunde and Informatica (CWI), Amsterdam Science Park, The Netherlands, March 11, (2010).
- Non-Stop Action: The Agent as a Database, Internal Seminar, Formal Epistemology Project, University of Leuven, Belgium, February 23, (2010).
- Epistemic Closure and Information Processing, International Workshop on the Philosophy of Information and Computing Sciences, Lorentz Centre, Leiden, The Netherlands, February 8-12, (2010).
- Mono-Agent Dynamics, LORI-II: The Second Workshop on Logic, Rationality, and
Interaction, Chonqing, China, October 8-11, (2009).
- Non-Commuting Residuation Models with Process Exclusion, PLS7: The Seventh Pan-Hellenic Logic Symposium, Patras, Greece, July 15-19, (2009).
- Negative Information and Informational Asymmetry, ECAP-09, Barcelona, Spain, July 02-04, (2009).
- Ajdukiewicz Functions and Basic Inference, Logica 2009: 23rd International Symposium, Hejnice Monastery, Czech Republic, June 22-26, (2009).
- Negation and Process, Philform, IHPST, The Sorbonne, Paris 1, France, April 27, (2009).
- A Procedural Interpretation of Split Negation, Logic Tea Colloquium, Institute for Logic, Language, and Computation (ILLC), University of Amsterdam, The Netherlands, September 15, (2008).
- Negative Information and Split Negation, Logica 2008: 22nd International Symposium, Hejnice Monastery, Czech Republic, June 16-20, (2008).
- Inferential Information-Gain and Negative Information, EPS-Research Seminar, Tilburg Institute for Logic and Philosophy of Science (TiLPS), Tilburg University, The Netherlands, March 27, (2008).
- Information Gain from Inference, LogKCA-07, International Workshop on Logic and Philosophy of Knowledge, ILCLI Rationality, and Action: Donostia – San Sebastian, Spain, 28-30 November, (2007).
- Revising Who’s Logic? – Reply to Hartry Field’s Revising Our Logic: Keynote at the 11th Annual Oxford Philosophy Graduate Conference,Faculty of Philosophy, University of Oxford, November 10-11, (2007).
- A Positive Information Logic, PIL-07, The First Workshop on the Philosophy of Information and Logic, IEG, Faculty of Philosophy, University of Oxford, 3-4 November, (2007).
- Metasemantic Information and the Scandal of Deduction, Logica 2007: 21st International Symposium, Hejnice Monastery, Czech Republic, June 18-22, (2007).
- From Semantic Information to Psychological Information, E-CAP 2006, European
Conference on Computing and Philosophy, Norwegian University of Science and Technology, Trondheim, Norway, June 22-24, (2006).