  We establish tools to facilitate the computation and application of the
Chekanov-Eliashberg differential graded algebra (DGA), a Legendrian-isotopy
invariant of Legendrian knots in standard contact three-space. More
specifically, we reformulate the DGA in terms of front projection, and
introduce the characteristic algebra, a new invariant derived from the DGA. We
use our techniques to distinguish between several previously indistinguishable
Legendrian knots and links.
