Thus, a one-way correlation was suggested between inflectional agreement (AGR) and empty pronouns on the one hand and between no agreement and overt pronouns, on the other.
The term pro-drop is also used in other frameworks in generative grammar, such as in lexical functional grammar (LFG), but in a more general sense: "Pro-drop is a widespread linguistic phenomenon in which, under certain conditions, a structural NP may be unexpressed, giving rise to a pronominal interpretation."