  Working in the axiomatic framework recently proposed by Gaberdiel and
Goddard, we prove a generalized version of Zhu's Theorem; for any chiral
bosonic conformal field theory on the sphere, our result characterizes the
chiral blocks in terms of a certain quotient of the Fock space. We also
establish, under a finiteness hypothesis closely related to rationality of the
theory, that the relevant Knizhnik-Zamolodchikov-type equation admits
solutions.
