We propose a strictly narrowly syntactic approach to semantic recovery of post-auxiliary ellipsis and sluicing based on a novel notion of syntactic identity between the antecedent and ellipsis site: we assume that the syntactic material present in the ellipsis site is built recursively by the copying of Agree and structural Case licensing relations. This accounts for the following phenomena: the relative acceptability of verbal ellipsis with nominal antecedents, voice alternations under ellipsis, differential islands repairing properties, complementary distribution between sluicing and local binding of pronouns as well as the surprising behavior of elliptical constructions in Maliseet, Frisian and spoken French. We derive our model from standard minimalist assumptions and interfaces effects and hence retrieve known syntactic properties (such as J.Merchant's generalization about preposition stranding under sluicing or S.Chung's characterization of the syntactic identity under sluicing) from first principles.