The 41 revised full research papers and 8 revised system descriptions presented together with 3 invited papers and a summary of a systems competition were carefully reviewed and selected from a total of 152 submissions. The papers address the entire spectrum of research in automated reasoning including formalization of mathematics, proof theory, proof search, description logics, interactive proof checking, higher-order logic, combination methods, satisfiability procedures, and rewriting. The papers are organized in topical sections on proofs, search, higher-order logic, proof theory, search, proof checking, combination, decision procedures, CASC-J3, rewriting, and description logic.