Consistency of super-Poincare covariant superstring tree amplitudes

Using pure spinors, the superstring was recently quantized in a manifestly ten-dimensional super-Poincare covariant manner and a covariant prescriptio n was given for tree-level scattering amplitudes. In this paper, we prove t hat this prescription is cyclically symmetric and, for the scattering of an arbitrary number of massless bosons and up to four massless fermions, it a grees with the standard Ramond-Neveu-Schwarz prescription.