 The SD argument does not go through as smoothly as some of its advocates have thought, however. There are difficult issues regarding the appropriate version of quantum mechanics (e.g., von Neumann, Bohmian or decoherence theories; see entries under  quantum mechanics),  the nature of quantum measurement theory (collapse vs. non-collapse theories; see the section on the measurement problem in  the entry on   philosophical issues in quantum theory), and the selection of the initial state characterizing the system that must be resolved before one can say clearly whether or not unique evolution is violated. For instance, just because quantum effects might influence macroscopic chaotic systems doesn’t guarantee that determinism fails for such systems. Whether quantum interactions with nonlinear macroscopic systems exhibiting SDIC contribute indeterministically to the outcomes of such systems depends on the currently undecidable question of indeterminism in quantum mechanics and the measurement problem as well as on how one chooses to the system-measurement apparatus cut (Bishop 2008). 