Professor Dr. habil.
Christoph Benzmüller

Freie Universität Berlin, Dep. of Maths and CS
University of Luxembourg, FSTC (Visiting Scholar)
Saarland University, Dep. of CS (Privatdozent)

Arnimallee 7, 14195 Berlin    Tel.: +49(0)30 838 52485

Bio Publications Presentations Teaching

    Professional Interests
My research activities are interfacing the areas of artificial intelligence, philosophy, mathematics, computer science, and natural language. I am particularly interested in the use of classical higher-order logic (HOL) as a universal meta-logic to automate various non-classical logics and to utilise them in topical application areas, including machine ethics & machine law (responsible AI), metaphysics (e.g. Gödel's ontological argument), mathematical foundations (e.g. category theory) and rational argumentation. My research activities also address the integration of automated reasoning, machine learning and agent-based architectures. I have a core expertise in classical higher-order logic (HOL), and I have contributed to its semantics and proof theory, and together with colleagues and students I have developed the Leo theorem provers for HOL. Leo-III has recently been identified in an independent evaluation study as an internationally leading universal theorem prover.      LEO-III wins LTB division at CASC-27
• Preprint (to appear in Artificial Intelligence): Designing Normative Theories of Ethical Reasoning: Formal Framework, Methodology, and Tool Support
Area Co-Chair for Logic and Computation of ESSLLI 2021
• Keynote (postponed): Ethico-legal governance of intelligent artificial agents - Can post-hoc normative reasoning competencies prevent AI systems from going rogue? The International Conferences on Logic and Artificial Intelligence, Zhejiang University, China, 2020
• Preprint: Computer-supported Analysis of Arguments in Climate Engineering, CLAR, 2020
• Preprint: A (Simplified) Supreme Being Necessarily Exists - Says the Computer!
• Preprint: Computer-supported Analysis of Positive Properties, Ultrafilters and Modal Collapse in Variants of Gödel's Ontological Argument, Bulletin of the Section of Logic,2020
• Preprint: Computer-supported Exploration of a Categorical Axiomatization of Modeloids, RAMiCS, 2020
• Appointed as National Contact Point in Germany (together with Ute Schmid, Bamberg) for the European AI network CLAIRE
• Leo-III wins CASC-27 world championships in LTB division; runner up in THF division (see news article, news)
• PC Co-Chair of CICM 2020: Conference on Intelligent Computer Mathematics, Bertinoro, Italy, 2020
• Co-Organiser of ARQNL 2020: Automated Reasoning in Quantified Non-Classical Logics
• PC Member: IJCAI 2020, IJCAR 2020, DEON 2020, KI 2020, GCAI 2020
• PC Co-Chair of KI 2019: Advances in Artificial Intelligence -- 42th Annual German Conference on AI, Kassel, Germany, 2019
• Article: Computer Science and Metaphysics: A Cross-Fertilization, Open Philosophy, 2019 (preprint)
• Article: Mechanizing Principia Logico-Metaphysica in Functional Type Theory, Review of Symbolic Logic, 2019 (preprint)
• Article: I/O Logic in HOL, Journal of Applied Logics, 2019 (preprint)
• Article: Aqvist's Dyadic Deontic Logic E in HOL, Journal of Applied Logics, 2019 (preprint)
• Article: Automating Free Logic in HOL, with an Experimental Application in Category Theory, Journal of Automated Reasoning, 2019 (online) (preprint)
• Book chapter: A Computational-Hermeneutic Approach for Conceptual Explicitation, Sapere, Springer, 2019 (preprint)
• Book chapter: A Case Study On Computational Hermeneutics: E. J. Lowe's Modal Ontological Argument, Sophia Studies in Cross-cultural Philosophy of Traditions and Cultures, Springer, 2019 (preprint)
• Paper: Harnessing Higher-Order (Meta-)Logic to Represent and Reason with Complex Ethical Theories, PRICAI 2019 (preprint)
• Paper: Mechanised Assessment of Complex Natural-Language Arguments using Expressive Logic Combinations, FroCoS 2019 (preprint)
• Paper: Computational Hermeneutics: An Integrated Approach for the Logical Analysis of Natural-Language Arguments, Logic in Asia: Studia Logica Library, Springer, 2019 (online) (preprint)
• Just published: Report on the Second International Joint Conference on Rules and Reasoning , AI Magazine, 2019 (online) (preprint)
• Just published: Church's Type Theory (update version), The Stanford Encyclopedia of Philosophy, 2019 (online)
• Just published: Universal (Meta-)Logical Reasoning: Recent Successes , Science of Computer Programming, 2019 (online) (preprint)
• Just published: Universal (Meta-)Logical Reasoning: The Wise Men Puzzle , Data in Brief, 2019 (online)
Performance at the 71st Science Slam in the legendary SO36 in Berlin-Kreuzberg
• Independent evaluation study identifies Leo-III as the world's leading (HO) automated theorem prover
• Nature Research Live in Berlin, Panel discussion on AI, March 19, 2019
• Preprint: What is a proof? What should it be?, January 2019
Kurt Gödel Workshop, FU Berlin, Feb 27, 2019
Keynote (video) at Mathematics and Reality conference (AISSQ 2018)
Keynote (video) at Intl. Conference on Deontic Logic and Normative Systems (DEON 2018)
• Mentor for EXIST Business Start-up Grant '7Markets'

    Research Group
Current and former PhD students (selection): Alexander Steen, Max Wisniewski, Daniel Kirchner, David Fuenmayor, Frank Theiss (Saarbrücken), Ali Farjami (Luxembourg, external supervisor), Sebastian Böhne (Potsdam, external supervisor), Marvin Schiller. Further current and former students (selection): Tobias Gleißner, Hanna Lachnitt, Irina Makarenko, Marc Nickert, Paul Podlech, David Streit, Lucca Tiemens, Valeria Zahoransky, Marco Ziener

    Computational Metaphysics and The Ontological Argument:
Our lecture concept on Computational Metaphysics won the central teaching award of Freie Universität Berlin. More information on the course: lecture course proposal and website/schedule.

In a collaboration with Bruno Woltzenlogel Paleo and others, I have analysed variants of Kurt Gödel's ontological argument for the existence of God on the computer. This work had a media repercussion on a global scale. There are various articles (e.g., Spiegel Online Intl., Die Welt, Wiener Zeitung, Spiegel Online) and interviews (e.g., Telepolis, PC Zoznam,, ORF); a selection of further links to reports worldwide is available here. Unfortunately, and probably unavoidable, there are also a few ill informed, trashy reports like this one. If you want to learn more about our scientific work (and about what we did and what we didn't), then you may have a look at our various papers some of which are listed at here.

    Main Projects (current and past)
CRAP: Consistent Rational Argumentation in Politics
LuxLI: Legal Informatics Luxembourg
LEO-III: Higher-Order Theorem Prover (DFG-Gepris)
CompMeta: Studies in Computational Metaphysics (DFG-Gepris)
ONTOLEO: Higher-Order Ontology-Reasoning with LEO-II (DFG-Gepris)
LEO-II: Higher-Order Theorem Prover
THFTPTP: An Infrastructure for Higher-order Automated Theorem Proving
OMEGA: Agent-oriented Proof Planning (DFG-Gepris)
DIALOG: NL-based Interaction with a Mathematics Assistance System (DFG-Gepris)
CALCULEMUS: Integration of Symbolic Reasoning and Symbolic Computation

    Board Memberships (selection):
CLAIRE-AI (key supporter), Conference on Automated Deduction, Association for Automated Reasoning, Society of Deontic Logic and Normative Systems, Berlin Mathematics Research Center MATH+, Berlin Mathematical School, Fachgruppe Deduktionssysteme der GI, IFCoLog, Logic Journal of the IGPL, Journal of Applied Logics, User Interfaces for Theorem Provers

    Recommended Recent Papers   (see also DBLP, Scholar, RG, ORBI^lu, ORCID ; my Erdös number is 3)
Please obey copyrights!
• Computer Science and Metaphysics: A Cross-Fertilization, March, 2019 (pdf)(doi)
• Designing Normative Theories of Ethical Reasoning: Formal Framework, Methodology, and Tool Support, March, 2019 (pdf)
• Automating Free Logic in HOL, with an Experimental Application in Category Theory, JAR, 2019 (pdf)
• Universal (Meta-)Logical Reasoning: Recent Successes, Science of Computer Programming, 2019 (pdf)
• Mechanizing Principia Logico-Metaphysica in Functional Type Theory, Review of Symbolic Logic, 2019 (pdf)
• Formalisation and Evaluation of Alan Gewirth's Proof for the Principle of Generic Consistency in Isabelle/HOL, AFP, 2018 (pdf)
• Axiom Systems for Category Theory in Free Logic, AFP, 2018 (pdf)
• A Dyadic Deontic Logic in HOL, DEON, 2018 (pdf)
• The Higher-Order Theorem Prover Leo-III, IJCAR 2018 (arXiv preprints), 2018. (pdf)
• A Deontic Logic Reasoning Infrastructure, CiE 2018, 2018. (pdf)
• Theorem Provers for Every Normal Modal Logic, LPAR, 2017. (pdf)
• Automating Emendations of the Ontological Argument in Intensional Higher-Order Modal Logic, KI, 2017. (pdf)
• Computer-Assisted Analysis of the Anderson-Hajek Controversy, Logica Universalis, 2017. (pdf)
• Cut-Elimination for Quantified Conditional Logic. J.Phil.Log., 2017. (pdf) (doi)
• The Modal Collapse as a Collapse of the Modal Square of Opposition, Studies in Universal Logic, 2016. (pdf)

    (Former) Hobbies
I was passionate middle and long-distance runner. In the early 90's I lived and trained at the Olympic Centre in Saarbrücken. In 1990 I was German Champion with the men's team in cross-country running. Feel free to beat some of my personal records: 2:25min (1000m), 3:49min (1500m), 8:14min (3000m), 14:13min (5000m), 30:04min (10000m).

C. Benzmüller (Last modified: Thu May 21 12:32:04 CEST 2020 )