R2-D2(archival copy) is a droid from StarWars. William Byrd is a person, who created a video titled Relational Programming in miniKanren by William Byrd, Part 1/2 and as of 2017_01 he is also the owner of the site minikanren.org(archival copy). The encoding format described in this blog post is totally useless from speed optimization point of view. This blog post is more about philosophy than math.
Thank You for reading :-)