§0 The pre-history of the topic --;§1 The grammar of the Q systems --;§2 The semantics of the Q systems --;§3 Descriptions --;§4 Statability atoms --;§5 Relevance conditions --;§6 Some irrefutable and refutable sentences --;§7 The Q calculi --;§8 Basic metatheorems on the Q calculi --;§9 Deductions. Further derived rules --;§10 Consistent and complete sets --;§11 Hypercomplete and compossible sets --;§12 Alternatives and successors of hypercomplete sets --;§13 Tree structures --;§14 The completeness theorem --;Appendix 1: Deontic logic --;References --;List of symbols --;List of abbreviations.