 The logic of negation may be presented in quite different ways, by considering various styles of proof systems (axiom systems, sequent calculi, systems of natural deduction, tableaux, etc.) or different kinds of semantics (algebraic, model-theoretic, proof-theoretic, game-theoretic, etc.). Moreover, in search of characteristics of negation as a one-place connective, several dimensions of classification are available, depending on the logical vocabulary of the language under consideration (propositional, first-order, multi-modal, etc.) and the inferential framework taken into account (single antecedents (i.e., premises) and conclusions, multiple antecedents or multiple conclusions, sets, multisets, or sequences of formulas in antecedent or succedent position).