This book constitutes the proceedings of the 20th
International Conference on Logic for Programming, Artificial Intelligence, and
Reasoning, LPAR-20, held in November 2015, in Suva, Fiji.

The 43 regular papers presented together with 1 invited
talk included in this volume were carefully reviewed and selected from 92
submissions. The series of International Conferences on Logic for Programming,
Artificial Intelligence and Reasoning, LPAR, is a forum where, year after year,
some of the most renowned researchers in the areas of logic, automated
reasoning, computational logic, programming languages and their applications
come to present cutting-edge results, to discuss advances in these fields, and
to exchange ideas in a scientifically emerging part of the world.