  The b ghost in the non minimal pure spinor formalism is not a fundamental
field. It is based on a complicated chain of operators and proving its
nilpotency is nontrivial. Chandia proved this property in arXiv:1008.1778, but
with an assumption on the non-minimal variables that is not valid in general.
In this work, the b ghost is demonstrated to be nilpotent without this
assumption.
