Classical modal logic: Difference between revisions

Revision as of 20:23, 6 June 2019

Revision as of 13:29, 28 October 2019

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<math> A \equiv B \vdash \Box A\equiv\Box B.</math>

Alternatively one can give a dual definition of '''L''' by which '''L''' is classical iffif it contains (as axiom or theorem)

<math>\Box A \equiv \lnot\Diamond\lnot A</math>