Universal 427: agreement in gender (within the NP) ⇒ agreement in gender (outside the NP)
Original
If there is any set of agreeing constituent types whose members show agreement in terms of semantically interpretable or “natural” gender properties, this set will include constituent types that are external to the noun phrase – that is to say, verbs and anaphoric pronouns. OR, putting it in another way: the occurrence of semantic or natural gender agreement within the noun phrase implies such agreement outside it in the same language.
Standardized
Whenever there is gender agreement, IF morphological gender can be overruled by semantics within the noun phrase, THEN it can also be overruled in noun phrase external gender agreement.
See Corbett’s Agreement Hierarchy.