Stefan Hetzl
Associate Prof. Dipl.-Ing. Dr.techn. / BSc
Research Areas
- Interactive theorem proving, Automated theorem proving, Proof Theory, Theory of formal Languages
About
Computational Logic, Proof Theory, Theory of Formal Languages, Automated theorem proving, Interactive theorem proving
Role
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Affiliated
Theory and Logic, E192-05
Courses
2024W
- Bachelor Thesis for Informatics and Business Informatics / 185.A26 / PR
- Project in Computer Science 1 / 192.021 / PR
- Project in Computer Science 2 / 192.022 / PR
- Research Seminar for Master and PhD students / 185.A39 / SE
2025S
- Bachelor Thesis for Informatics and Business Informatics / 185.A26 / PR
- Project in Computer Science 1 / 192.021 / PR
- Project in Computer Science 2 / 192.022 / PR
- Research Seminar for Master and PhD students / 185.A39 / SE
Projects
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Automated Analysis of Mathematical Proofs
2005 – 2007 / Austrian Science Fund (FWF)
Publications
2019
- Expansion trees with cut / Aschieri, F., Hetzl, S., & Weller, D. (2019). Expansion trees with cut. Mathematical Structures in Computer Science, 29(8), 1009–1029. https://doi.org/10.1017/s0960129519000069
2017
- Preface / Baaz, M., Ciabattoni, A., Gabbay, D. M., Hetzl, S., & Weller, D. (2017). Preface. Journal of Logic and Computation, 27(2), 415–415. https://doi.org/10.1093/logcom/exu076
2016
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System Description: GAPT 2.0
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Ebner, G., Hetzl, S., Reis, G., Riener, M., Wolfsteiner, S. P., & Zivota, S. (2016). System Description: GAPT 2.0. In Automated Reasoning (pp. 293–301). Springer. https://doi.org/10.1007/978-3-319-40229-1_20
Project: ASCP (2013–2016)
2014
- Algorithmic introduction of quantified cuts / Hetzl, S., Leitsch, A., Reis, G., & Weller, D. (2014). Algorithmic introduction of quantified cuts. Theoretical Computer Science, 549, 1–16. https://doi.org/10.1016/j.tcs.2014.05.018
- Introducing Quantified Cuts in Logic with Equality / Leitsch, A., Hetzl, S., Reis, G., & Weller, D. (2014). Introducing Quantified Cuts in Logic with Equality. arXiv. https://doi.org/10.48550/arXiv.1402.2474
- Algorithmic Introduction of Quantified Cuts / Hetzl, S., Reis, G., & Weller, D. (2014). Algorithmic Introduction of Quantified Cuts. arXiv. https://doi.org/10.48550/arXiv.1401.4330
- Introducing Quantified Cuts in Logic with Equality / Hetzl, S., Leitsch, A., Reis, G., Tapolczai, J., & Weller, D. (2014). Introducing Quantified Cuts in Logic with Equality. In Automated Reasoning (pp. 240–254). LNCS 8562. https://doi.org/10.1007/978-3-319-08587-6_17
2013
- Herbrand-Confluence / Hetzl, S., & Strassburger, L. (2013). Herbrand-Confluence. Logical Methods in Computer Science, 9(4). https://doi.org/10.2168/LMCS-9(4:24)2013
2012
- Towards Algorithmic Cut-Introduction / Leitsch, A., Hetzl, S., & Weller, D. (2012). Towards Algorithmic Cut-Introduction. In N. Bjørner & A. Voronkov (Eds.), Logic for Programming, Artificial Intelligence, and Reasoning (pp. 228–242). Springer LNCS. https://doi.org/10.1007/978-3-642-28717-6_19
2011
- On the non-confluence of cut-elimination / Baaz, M., & Hetzl, S. (2011). On the non-confluence of cut-elimination. Journal of Symbolic Logic, 76(1), 313–340. https://doi.org/10.2178/jsl/1294171002
- Ceres in higher-order logic / Hetzl, S., Leitsch, A., & Weller, D. (2011). Ceres in higher-order logic. Annals of Pure and Applied Logic, 162(12), 1001–1034. https://doi.org/10.1016/j.apal.2011.06.005
2010
- On the complexity of proof deskolemization / Baaz, M., Hetzl, S., & Weller, D. (2010). On the complexity of proof deskolemization. Collegium Locicum 2010: Proofs and Structures, Paris, EU. http://hdl.handle.net/20.500.12708/85099
- CERES in higher-order-logic / Hetzl, S., Leitsch, A., & Weller, D. (2010). CERES in higher-order-logic. Workshop on Classical Logic and Computation (CL&C’10), Brünn, EU. http://hdl.handle.net/20.500.12708/85096
2009
- A Clausal Approach to Proof Analysis in Second-Order Logic / Hetzl, S., Leitsch, A., Weller, D., & Woltzenlogel-Paleo, B. (2009). A Clausal Approach to Proof Analysis in Second-Order Logic. In A. Nerode & S. Artemov (Eds.), LFCS 2009: Logical Foundations of Computer Science (pp. 214–229). Springer, LNCS. https://doi.org/10.1007/978-3-540-92687-0_15
2008
- CERES: An analysis of Fürstenberg's proof of the infinity of primes / Baaz, M., Hetzl, S., Leitsch, A., Richter, C., & Spohr, H. (2008). CERES: An analysis of Fürstenberg’s proof of the infinity of primes. Theoretical Computer Science, 403(2–3), 160–175. https://doi.org/10.1016/j.tcs.2008.02.043
- Cut-elimination / Baaz, M., & Hetzl, S. (2008). Cut-elimination. Third Vienna Tbilisi Summer School in Logic and Language, Tbilisi, Georgia, Non-EU. http://hdl.handle.net/20.500.12708/118581
- Herbrand Sequent Extraction / Leitsch, A., Hetzl, S., Weller, D., & Woltzenlogel-Paleo, B. (2008). Herbrand Sequent Extraction. In S. Autexier (Ed.), AISC/Calculemus/MKM 2008 (pp. 462–477). Springer. http://hdl.handle.net/20.500.12708/52369
- Proof Analysis with HLK, CERES and ProofTool: Current Status and Future Directions / Leitsch, A., Hetzl, S., Weller, D., & Woltzenlogel-Paleo, B. (2008). Proof Analysis with HLK, CERES and ProofTool: Current Status and Future Directions. In G. Sutcliffe, S. Colton, & S. Schulz (Eds.), Proceedings of the CICIM Workshops on ESARM-08 (pp. 23–41). CEUR-WS.org. http://hdl.handle.net/20.500.12708/52368
- Transforming and Analyzing Proofs in the CERES-system / Leitsch, A., Hetzl, S., Weller, D., & Woltzenlogel-Paleo, B. (2008). Transforming and Analyzing Proofs in the CERES-system. In P. Rudnicki & G. Sutcliffe (Eds.), Proceedings of the LPAR 2008 Workshops (pp. 77–91). CEUR-WS.org. http://hdl.handle.net/20.500.12708/52364
2007
- Proof Transformations and Structural Invariance / Leitsch, A., & Hetzl, S. (2007). Proof Transformations and Structural Invariance. In S. Aguzzoli (Ed.), LNAI 4460: Algebraic and Proof-theoretic Aspects (pp. 201–230). Springer, LNAI 4460. http://hdl.handle.net/20.500.12708/25413
- Characteristic clause sets and proof transformations / Hetzl, S. (2007). Characteristic clause sets and proof transformations [Dissertation, Technische Universität Wien]. reposiTUm. http://hdl.handle.net/20.500.12708/183195
2006
- A Similarity Criterion for Proofs (abstract) / Hetzl, S. (2006). A Similarity Criterion for Proofs (abstract). In A. Beckmann, U. Berger, B. Löwe, & J. V. Tucker (Eds.), Logical Approaches to Computational Barriers (p. 295). University of Wales Swansea Report Series. http://hdl.handle.net/20.500.12708/51677
- System Description: The Cut-Elimination System CERES / Baaz, M., Hetzl, S., Leitsch, A., Richter, C., & Spohr, H. (2006). System Description: The Cut-Elimination System CERES. In G. Sutcliffe, R. Schmidt, & S. Schulz (Eds.), ESCoR 2006 Empirically Successful Computerized Reasoning (p. 9). CEUR Workshop Proceedings. http://hdl.handle.net/20.500.12708/176627
- Proof transformation by CERES / Baaz, M., Hetzl, S., Leitsch, A., Richter, C., & Spohr, H. (2006). Proof transformation by CERES. Lecture Notes in Computer Science, 82–93. https://doi.org/10.1007/11812289_8
- Comparing Mathematical Proofs / Hetzl, S. (2006). Comparing Mathematical Proofs. Studia Logica International Conference; Towards Mathematical Philosophy; Trends in Logic IV, Torun, Poland, EU. http://hdl.handle.net/20.500.12708/84554
- Proof Transformation by CERES / Baaz, M., Hetzl, S., Leitsch, A., Richter, C., & Spohr, H. (2006). Proof Transformation by CERES. In J. M. Borwein & W. Farmer (Eds.), MKM 2006 (pp. 82–93). Springer. http://hdl.handle.net/20.500.12708/51679
2005
- A Graph-Theoretic Approach to Steganography / Hetzl, S., & Mutzel, P. (2005). A Graph-Theoretic Approach to Steganography. In J. Dittmann, S. Katzenbeisser, & A. Uhl (Eds.), 9th IFIP Conference on Communications and Multimedia Security (CMS 2005) (pp. 119–128). Springer. http://hdl.handle.net/20.500.12708/51077
- Abstracting from the Propositional Structure of First-Order Proofs / Hetzl, S., & Leitsch, A. (2005). Abstracting from the Propositional Structure of First-Order Proofs. Paris-Vienna Workshop 2005, Paris, EU. http://hdl.handle.net/20.500.12708/84469
- Cut-Elimination: Experiments with CERES / Baaz, M., Hetzl, S., Leitsch, A., Richter, C., & Spohr, H. (2005). Cut-Elimination: Experiments with CERES. Second Florence-Vienna Workshop on Logic and Computation, Florence, Italy, Austria. http://hdl.handle.net/20.500.12708/84468
- Cut-Elimination: Experiments with CERES / Baaz, M., Hetzl, S., Leitsch, A., Richter, C., & Spohr, H. (2005). Cut-Elimination: Experiments with CERES. In LOgic for Programming, Artificial Intelligence, and Reasoning (pp. 481–495). Springer, LNAI. http://hdl.handle.net/20.500.12708/51011
2004
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Projection-based cut-elimination and normalization
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Hetzl, S. (2004). Projection-based cut-elimination and normalization [Diploma Thesis, Technische Universität Wien]. reposiTUm. https://resolver.obvsg.at/urn:nbn:at:at-ubtuw:1-10645
Download: PDF (338 KB)
Supervisions
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Grammatical complexity of finite languages
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Wolfsteiner, S. P. (2020). Grammatical complexity of finite languages [Dissertation, Technische Universität Wien]. reposiTUm. https://doi.org/10.34726/hss.2020.80501
Download: PDF (1.27 MB) -
Zyklische Superposition und Induktion
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Vierling, J. (2018). Zyklische Superposition und Induktion [Diploma Thesis, Technische Universität Wien]. reposiTUm. https://doi.org/10.34726/hss.2018.51282
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