A No-Go Theorem for Joint Property Ascriptions in Modal Interpretations of Quantum Mechanics

With an interpretation of quantum mechanics one can not only predict probabilities for outcomes of measurements performed on quantum systems but also ascribe properties to these systems themselves. I consider interpretations (notably modal interpretations) that ascribe at least those properties to a system which are represented by the eigenprojections of the reduced state. Such interpretations solve the measurement problem for ideal measurements. Here, however, I prove that these interpretations cannot define joint property ascriptions to three or more systems.