A connection between holomorphic and generating family invariants of
Legendrian knots is established; namely, that the existence of a ruling (or
decomposition) of a Legendrian knot is equivalent to the existence of an
augmentation of its contact homology. This result was obtained independently
and using different methods by Fuchs and Ishkhanov. Close examination of the
proof yields an algorithm for constructing a ruling given an augmentation.
Finally, a condition for the existence of an augmentation in terms of the
rotation number is obtained.Comment: 21 pages, 16 figure
