  The results of finite-size scaling analysis of histogram Monte-Carlo
simulations on the stacked triangular XY antiferromagnet with anisotropic
near-neighbor exchange interactions are presented. With ferromagnetic
interplane coupling ten times stronger than the antiferromagnetic intraplane
interaction ($J_\| / J_\bot = -10$), a weak first-order transition is revealed.
These results represents the first simulational corroboration of a wide variety
of renormalization-group calculations made over the past twenty years. As such,
they shed light on recent controversy regarding the critical behavior in this
and similar frustrated systems and have particular relevance to recently
reported data on $CsCuCl_3$.
