The three reviews agree that the paper develops strong theoretical results regarding an important topic. Also the techniques are interesting, and the paper is well written. The main negative aspect in the reviews concerns the practical applicability of the results. Although the authors address this in their reply, the reviewers after discussion are not really convinced about the potential for bridging the gap between theory and practice. Regardless of this, the reviewers are clear in their assessment that the work deserves publications purely on the strength of the theoretical contribution.