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In modal logic, standard translation is a way of transforming formulas of modal logic into formulas of first-order logic which capture the meaning of the modal formulas. Standard translation is defined inductively on the structure of the formula. In short, atomic formulas are mapped onto unary predicates and the objects in the first-order language are the accessible worlds. The logical connectives from propositional logic remain untouched and the modal operators are transformed into first-order formulas according to their semantics. == Definition == Standard translation is defined as follows: *, where is an atomic formula; P(x) is true when holds in world . * * * * * * * * In the above, is the world from which the formula is evaluated. Initially, a free variable is used and whenever a modal operator needs to be translated, a fresh variable is introduced to indicate that the remainder of the formula needs to be evaluated from that world. Here, the subscript refers to the accessibility relation that should be used: normally, and refer to a relation of the Kripke model but more than one accessibility relation can exist (a multimodal logic) in which case subscripts are used. For example, and refer to an accessibility relation and and to in the model. Alternatively, it can also be placed inside the modal symbol. 抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「Standard translation」の詳細全文を読む スポンサード リンク
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