  Recently, the existence of a candidate a-function for renormalisable theories
in three dimensions was demonstrated for a general theory at leading order and
for a scalar-fermion theory at next-to-leading order. Here we extend this work
by constructing the a-function at next-to-leading order for an N=2
supersymmetric Chern-Simons theory. This increase in precision for the
a-function necessitated the evaluation of the underlying renormalization-group
functions at four loops.
