This project explores the constraints placed on anaphoric relations between expressions in the scope of non-veridical operators, in particular negation. While different factors constrain anaphoric co-reference, I argue that the constraints that standard DRT (like the other classic dynamic frameworks) captures intra-sententially using the accessibility relation can be generalized to cross-sentential anaphora by appealing to generalizations in terms of veridicality relative to the discourse commitments of a speaker.