This volume contains the research papers presented at the 17th International Conference on Logic for Programming, Arti?cial Intelligence, and Reasoning (LPAR-17), held in Yogyakarta, Indonesia, October 10-15, 2010, accompanied by the 8th International Workshop on the Implementation of Logic (IWIL-8, organized by Eugenia Ternovska, Stephan Schulz, and Geo? Sutcli?e) and the 5th International Workshop on Analytic Proof Systems (APS-5, organized by Matthias Baaz and Christian Fermuller .. ). The call for papers attracted 133 abstract submissions of which 105 ma- rialized into full submissions, each of which was assigned for reviewing to at least three Program Committee members; 41 papers were accepted after - tense discussions. Once more the EasyChair system provided an ideal platform for submission, reviewing, discussions, and collecting ?nal versions of accepted papers. The program included three invited talks by Krishnendu Chatterjee, Joseph Halpern, and Michael Maher, as well as an invited tutorial by Norbert Preining. They are documented by the corresponding papers and abstract, respectively, in these proceedings, which this year appear for the ?rst time in the ARCoSS subline of the Lecture Notes in Computer Science.

This volume contains the research papers presented at the 17th International Conference on Logic for Programming, Arti?cial Intelligence, and Reasoning (LPAR-17), held in Yogyakarta, Indonesia, October 10-15, 2010, accompanied by the 8th International Workshop on the Implementation of Logic (IWIL-8, organized by Eugenia Ternovska, Stephan Schulz, and Geo? Sutcli?e) and the 5th International Workshop on Analytic Proof Systems (APS-5, organized by Matthias Baaz and Christian Fermuller .. ). The call for papers attracted 133 abstract submissions of which 105 ma- rialized into full submissions, each of which was assigned for reviewing to at least three Program Committee members; 41 papers were accepted after - tense discussions. Once more the EasyChair system provided an ideal platform for submission, reviewing, discussions, and collecting ?nal versions of accepted papers. The program included three invited talks by Krishnendu Chatterjee, Joseph Halpern, and Michael Maher, as well as an invited tutorial by Norbert Preining. They are documented by the corresponding papers and abstract, respectively, in these proceedings, which this year appear for the ?rst time in the ARCoSS subline of the Lecture Notes in Computer Science.