  We are in the process of testing a popular theory that the observed abundance
anomalies in the Globular Cluster NGC 6752 are due to `internal pollution' from
intermediate mass asymptotic giant branch stars. To this end we are using a
chemical evolution model incorporating custom-made stellar evolution yields
calculated using a detailed stellar evolution code. By tracing the chemical
evolution of the intracluster gas, which is polluted by two generations of
stars, we are able to test the internal pollution scenario in which the Na- and
Al-enhanced ejecta from intermediate mass stars is either accreted onto the
surfaces of other stars, or goes toward forming new stars.
  In this paper we focus mainly on the nucleosynthetic yields of the AGB stars
and discuss whether these stars are the source of the observed Na-O
anticorrelation. Comparing our preliminary results with observational data
suggests that the qualitative theory is not supported by this quantitative
study.
