Logic Programming and Non-monotonic
      Reasoning from 1991 to 2019: a Personal
                    Perspective

                                Michael Gelfond

                           Texas Tech University, USA
                           michael.gelfond@ttu.edu

    The field of logic programming and nonmonotic reasoning was born in 1991,
when a number of researchers working in “the theoretical ends” of logic pro-
gramming and artificial intelligence gathered in Washington D.C. for the first
LPNMR workshop, which was organized by Anil Nerode, Wiktor Marek, and
V.S. Subrahmanian. I was privileged to attend this meeting; to closely observe
the development of the field over the past 28 years; and to witness many remark-
able achievements, which in 1991 I would not have believed to be possible. In this
talk I plan to discuss some of these achievements and share a number of personal
observations on the field’s history, current state, and possible future directions.
Among other things, I will comment on the development of powerful knowledge
representation languages, the design and implementation of non-monotonic rea-
soning systems, and use of these languages and systems in formalizing various
types of knowledge and reasoning tasks. The talk is not meant to be a survey of
the field, rather it is my personal perspective limited to a small, but important,
collection of topics I am most familiar with.