This open access book constitutes the proceeding of the 28th International Conference on Automated Deduction, CADE 28, held virtually in July 2021. The 29 full papers and 7 system descriptions presented together with 2 invited papers were carefully reviewed and selected from 76 submissions. CADE is the major forum for the presentation of research in all aspects of automated deduction, including foundations, applications, implementations, and practical experience. The papers are organized in the following topics: Logical foundations; theory and principles; implementation and application; ATP and AI; and system descriptions.

This volume contains the papers presented at the Ninth International Conference on Automated Deduction (CADE-9) held May 23-26 at Argonne National Laboratory, Argonne, Illinois. The conference commemorates the twenty-fifth anniversary of the discovery of the resolution principle, which took place during the summer of 1963. The CADE conferences are a forum for reporting on research on all aspects of automated deduction, including theorem proving, logic programming, unification, deductive databases, term rewriting, ATP for non-standard logics, and program verification. All papers submitted to the conference were refereed by at least two referees, and the program committee accepted the 52 that appear here. Also included in this volume are abstracts of 21 implementations of automated deduction systems.

This book constitutes the proceedings of the 24th International Conference on Automated Deduction, CADE-24, held in Lake Placid, NY, USA, in June 2013. The 31 revised full papers presented together with 2 invited papers were carefully reviewed and selected from 71 initial submissions. CADE is the major forum for the presentation of research in all aspects of automated deduction, ranging from theoretical and methodological issues to the presentation of new theorem provers, solvers and systems.

This book constitutes the refereed proceedings of the 16th International Conference on Automated Deduction, CADE-16, held in Trento, Italy in July 1999 as part of FLoC'99. The 21 revised full papers presented were carefully reviewed and selected from a total of 83 submissions. Also included are 15 system descriptions and two invited full papers. The book addresses all current issues in automated deduction and theorem proving, ranging from logical foundations to deduction systems design and evaluation

The refereed proceedings of the 19th International Conference on Automated Deduction, CADE 2003, held in Miami Beach, FL, USA in July 2003. The 29 revised full papers and 7 system description papers presented together with an invited paper and 3 abstracts of invited talks were carefully reviewed and selected from 83 submissions. All current aspects of automated deduction are discussed, ranging from theoretical and methodological issues to the presentation of new theorem provers and systems.

For the past 25 years the CADE conference has been the major forum for the presentation of new results in automated deduction. This volume contains the papers and system descriptions selected for the 17th International Conference on Automated Deduction, CADE-17, held June 17-20, 2000,at Carnegie Mellon University, Pittsburgh, Pennsylvania (USA). Fifty-three research papers and twenty system descriptions were submitted by researchers from ?fteen countries. Each submission was reviewed by at least three reviewers. Twenty-four research papers and ?fteen system descriptions were accepted. The accepted papers cover a variety of topics related to t- orem proving and its applications such as proof carrying code, cryptographic protocol veri?cation, model checking, cooperating decision procedures, program veri?cation, and resolution theorem proving. The program also included three invited lectures: “High-level veri?cation using theorem proving and formalized mathematics” by John Harrison, “Sc- able Knowledge Representation and Reasoning Systems” by Henry Kautz, and “Connecting Bits with Floating-Point Numbers: Model Checking and Theorem Proving in Practice” by Carl Seger. Abstracts or full papers of these talks are included in this volume.In addition to the accepted papers, system descriptions, andinvited talks, this volumecontains one page summaries of four tutorials and ?ve workshops held in conjunction with CADE-17.

The Seventh International Conference on Automated Deduction was held May 14-16, 19S4, in Napa, California. The conference is the primary forum for reporting research in all aspects of automated deduction, including the design, implementation, and applications of theorem-proving systems, knowledge representation and retrieval, program verification, logic programming, formal specification, program synthesis, and related areas. The presented papers include 27 selected by the program committee, an invited keynote address by Jorg Siekmann, and an invited banquet address by Patrick Suppes. Contributions were presented by authors from Canada, France, Spain, the United Kingdom , the United States, and West Germany. The first conference in this series was held a decade earlier in Argonne, Illinois. Following the Argonne conference were meetings in Oberwolfach, West Germany (1976), Cambridge, Massachusetts (1977), Austin, Texas (1979), Les Arcs, France (19S0), and New York, New York (19S2). Program Committee P. Andrews (CMU) W.W. Bledsoe (U. Texas) past chairman L. Henschen (Northwestern) G. Huet (INRIA) D. Loveland (Duke) past chairman R. Milner (Edinburgh) R. Overbeek (Argonne) T. Pietrzykowski (Acadia) D. Plaisted (U. Illinois) V. Pratt (Stanford) R. Shostak (SRI) chairman J. Siekmann (U. Kaiserslautern) R. Waldinger (SRI) Local Arrangements R. Schwartz (SRI) iv CONTENTS Monday Morning Universal Unification (Keynote Address) Jorg H. Siekmann (FRG) .