
C1: Extended Unification and its Implementation. Proceedings of the German Workshop on Artificial Intelligence, Informatik Fachberichte 118, Springer, 176-185: 1985 (together with U. Furbach and T. Laußermair).
C2: A Unification Algorithm for Confluent Theories. Proceedings of the International Conference on Automata, Languages, and Programming, Lecture Notes in Computer Science 267, Springer, 31-41: 1987.
C3: Equational Logic Programming. Proceedings of the Symposium on Logic Programming, IEEE, 335-346: 1987.
C4: From Paramodulation to Narrowing. Proceedings of the 5th International Conference and Symposium on Logic Programming, MIT Press, 327-342: 1988.
C5: Horn Equality Theories and Complete Sets of Transformations. Proceedings of the International Conference on Fifth Generation Computer Systems, ICOT, 405-412: 1988.
C6: Linear Paramodulation modulo Equality. Proceedings of the German Workshop on Artificial Intelligence, Springer, 107-116: 1989 (together with U. Furbach and J. Schreiber).
C7: A new Deductive Approach to Planning. Proceedings of the German Workshop on Artificial Intelligence, Springer, 63-73: 1989 (together with J. Schneeberger).
C8: A Structured Connectionist Unification Algorithm. Proceedings of the AAAI National Conference on Artificial Intelligence, 587-593: 1990.
C9: On High Level Inferencing and the Variable Binding Problem in Connectionist Networks. Proceedings der Oesterreichischen Artificial Intelligence Tagung, 180-185: 1990.
C10: Towards a Connectionist Inference System. In: Computational Intelligence III (N. Cercone, F. Gardin, G. Valle, eds.), North Holland, 25-38: 1991.
C11: Constraint Satisfaction in a Connectionist Inference System. Proceedings of the 4th International Symposium on Artificial Intelligence, 215-221: 1991 (together with W. Hower).
C12: Cycle Unification. Proceedings of the 11th International Conference on Automated Deduction, Springer, LNAI 607, 94-108: 1992 (together with W. Bibel and J. Wuertz).
C13: On Deductive Planning and the Frame Problem. Proceedings of the Conference on Logic Programming and Automated Reasoning, Springer, Lecture Notes in Artificial Intelligence 624, 13-19: 1992.
C14: Equational Logic Programming, Actions, and Change. Proceedings of the Joint International Conference and Symposium on Logic Programming. MIT Press, 177-191, 1992 (together with G. Grosse, J. Schneeberger, U. Sigmund and M. Thielscher).
C15: On the Adequateness of the Connection Method. Proceedings of the National Conference on Artificial Intelligence, 9-14: 1993 (together with A. Beringer).
C16: Spatial Reasoning and Connectionist Inference. Proceedings of the International Joint Conference on Artificial Intelligence, 1993 (together with A. Beringer and F. Kurfeß).
C17: Actions and Specificity. Proceedings of the International Symposium on Logic Programming, 164-180: 1993 (together with M. Thielscher).
C18: Disjunction in Resource-Oriented Deductive Planning. Proceedings of the International Symposium on Logic Programming, 670: 1993 (together with S. Brüning, J. Schneeberger, U. Sigmund and M. Thielscher).
C19: On the Adequateness of AI Systems. Proceedings of the Sixth International Conference on Artificial Intelligence and Information-Control Systems of Robots (I. Plander, ed.): 41-46, 1994 (together with M. Thielscher).
C20: An Abstract Machine for Reasoning about Situations, Actions, and Causality. Proceedings of the International Workshop on Extensions of Logic Programming, Lecture Notes in Artificial Intelligence 1050, Springer, 137-151: 1996 (together with K. Eder und M. Thielscher).
C21: Fuzzy Conceptual Knowledge Processing. Proceedings of the ACM Symposium on Applied Computing (SAC), Philadelphia: 1996 (together with C. Herrmann und A. Strohmaier).
C22: Designing a Counter: Another Case Study of Dynamics and Activation Landscapes in Recurrent Networks. Proceedings of the KI97: Advances in Artificial Intelligence, Lecture Notes in Artificial Intelligence 1303, 313-324: 1997 (together with Y. Kalinke and H. Lehmann).
C23: Recurrent Neural Networks to Approximate the Semantics of Logic Programs. Proceedings of the 11th Australian Joint Conference on Artificial Intelligence, Lecture Notes in Artificial Intelligence 1502, Springer: 1998 (together with Y. Kalinke and H. P. Störr).
C24: Descriptions in the Fluent Calculus. Proceedings of the International Conference on Artificial Intelligence, CSREA Press, 1311-1317: 2000.
C25: Solving the Entailment Problem in the Fluent Calculus with Binary Decision Diagrams. Proceedings of the First International Conference on Computational Logic, Lecture Notes in Artificial Intelligence 1861, 747-761: 2000 (together with H. P. Störr).
C26: The Boundary between Decidable and Undecidable Fragments of the Fluent Calculus. Proceedings of the 7th International Conference on Logic for Programming and Automated Reasoning, Lecture Notes in Artificial Intelligence 1955, Springer, 436-450: 2000 (together with D. Kuske).
C27: User Adaptation in a Web Shop System. Proceedings of the IASTED International Conference Internet and Multimedia Systems and Applications, ACTA Press, Anaheim, 208-213: 2001 (together with S.-E. Bornscheuer, Y. McIntyre and H. P. Störr).
C28: Incremental Fuzzy Decision Trees. Proceedings of the 25th German Conference on Artificial Intelligence (KI2002), Springer, 67-81: 2002 (together with M. Guetova and H.-P. Störr).
C29: Symbolic Dynamic Programming within the Fluent Calculus. Proceedings of the IASTED International Conference Artificial and Computational Intelligence, 378-383: 2002 (together with A. Grossmann and O. Skvortsova).
C30: A Fuzzy Description Logic with Hedges as Concept Modifiers. Proceedings of the Third International Conference on Intelligent Technologies and Third Vietnam-Japan Symposium on Fuzzy Systems and Applications, 25-34: 2002 (together with Tran Dinh Khang and H.-P. Störr).
C31: The Subsumption Problem in the Fuzzy Description Logic ALC_FH. Proceedings Tenth International Conference IPMU 2004: Information Processing and Managment of Uncertainty in Knowledge-Based Systems, 243-250: 2004 (together with Tran Dinh Khang and H.-P. Störr).
C32: Semiring Artificial Neural Networks and Weighted Automata -- and an Application to Digital Image Encoding. KI 2004: Advances in Artificial Intelligence, Lecture Notes in Artificial Intelligence 3238, 281-294: 2004 (zusammen mit S.~Bader und A.~Scalzitti).
C33: The Integration of Connectionism and First-Order Knowledge Representation and Reasoning as a Challenge for Artificial Intelligence. Proceedings Third International Conference on Information, 22-33: 2004 (together with S. Bader and P. Hitzler).
C34: The Fuzzy Description Logic ALC_FLH. Proceedings of the Ninth IASTED International Conference on Artificial Intelligence and Soft Computing. 99-104: 2005 (together with N. H. Nga and T. D. Khang).
C35: The Fuzzy Linguistic Description Logic ALC_FL. Proceedings of the Eleventh International Conference on Information Processing and Management of Uncertainty in Knowledge-Based Systems (IPMU), 2096-2103: 2006 (together with Dinh-Khac Dzung and Tran Dinh-Khang).
C36: The Core Method: Connectionist Model Generation. Proceedings of the 16th International Conference on Artificial Neural Networks (ICANN), LNCS 4132, 1-13: 2006 (together with S. Bader).
C37: A Fully Connectionist Model Generator for Covered First-Order Logic Programs Proceedings of the Twentieth International Joint Conference on Artificial Intelligence (IJCAI), 666-671: 2007 (together with S. Bader, P. Hitzler and A. Witzel.
C38: Neuro-Symbolic Word Tagging New Trends in Artificial Intelligence, APPIA - Associacao Portuguesa para a Inteligencia Artificial Edition (ISBN-13 978-989-95618-0-9), Guimaraes. Portugal: 779-790:2007 (together with S. Bader, N.C. Marques and V. Rocio).