In this paper, some algebraic properties of autodense languages and pure
autodense languages are studied. We also investigate the algebraic properties concerning
anti-autodense languages. The family of anti-autodense languages contains infix codes,
comma-free codes, and some subfamilies of new codes which are anti-autodense prefix
codes, anti-autodense suffix codes and anti-autodense codes. The relationships among these
subfamilies of new codes are investigated. The characterization of Ln, n ? 2, which are
anti-autodense is studied.
