It has often been suggested (Asher, 1993;Hardt, 1997;Hardt and Romero, 2004) that the antecedent selection process is very closely tied to discourse relations, in the sense that there is a strong preference or even a requirement for a discourse relation between the antecedent and ellipsis.
analysis of the annotated corpus data reveals surprising ambiguity in the identification of the antecedent for sluicing.