  The two- and three-point functions and the four-gluon vertex of
three-dimensional Yang-Mills theory are calculated from their Dyson-Schwinger
equations and the 3PI effective action. Within a self-contained truncation
various effects of truncating Dyson-Schwinger equations are studied. Estimates
for the errors induced by truncations are derived from comparisons between
results from different equations, comparisons with lattice results, and varying
higher Green functions. The results indicate that the two-loop diagrams are
important in the gluon propagator, where they are explicitly calculated, but
not for the vertices. Furthermore, the influence of the four-gluon vertex on
lower Green functions is found to be small.
