Appeal to standard set theory in minimalist syntax is shown to be in conflict with the goal of analyzing dependency formation, a.k.a. movement, as involving genuine constituent copies. The underlying tension is due to extensionality, which—other things being equal—favors a perspective on dependencies in terms of multidominance. The above argument is developed against the backdrop of a recent exposition of minimalist syntax :229–261, 2019), which can be seen as exemplary. The resulting critical assessment should be taken as removing obstacles on (...) the way toward proper minimalist foundations for syntactic theory. (shrink)