  A topological sigma model based on the pure spinor formalism was recently
proposed for the small radius limit of the AdS_5xS^5 superstring. Physical
states in this model can be constructed by connecting holes on the worldsheet
with Wilson lines of the worldsheet gauge field. The contribution of these
states to the topological amplitude is claimed to reproduce the usual Feynman
diagram expansion of gauge-invariant super-Yang-Mills correlation functions.
