|
( Modal logic)
Modal logic is a type of formal logic that extends the standards of formal logic to include the elements of modality (for example, possibility and necessity). Modals qualify the truth of a judgment. For example, if it is true that "John is happy," we might qualify this statement by saying that "John is very happy," in which case the term "very" would be a modality. Traditionally, there are three "modes" or "moods" or "modalities" represented by modal logic, namely, possibility, probability, and necessity. A formal modal logic represents modalities using modal operators. For example, "It might rain today" and "It is possible that rain will fall today" both contain the notion of possibility. In a modal logic this is represented as an operator, Possibly, attached to the sentence It will rain today. The basic unary (1-place) modal operators are usually written  for Necessarily and  for Possibly. In a classical modal logic, each can be expressed by the other with negation Thus it is possible that it will rain today if and only if it is not necessary that it will not rain today.
|
Modal logic Subcategories
Modal logic Articles
|
|
