EntityQ5300067· pop 10· linked from 102 articlesdouble negationSign in to savetheoremConnectionsrule of inferenceEntityrule of replacementEntityGeorg Wilhelm Friedrich HegelEntityBertrand RussellEntityInternational Standard Book NumberEntitytheoremEntityAlfred North WhiteheadEntitycommutative propertyEntityassociativityEntityinferenceEntitypropositional calculusEntityequivalence relationEntitydistributive propertyEntitylogical negationEntityDe Morgan's lawsEntitylitotesEntityJan ŁukasiewiczEntitytautologyEntityprinciple of excluded middleEntityfirst-order logicEntityCategoriesClassical logicRules of inferenceTheorems in propositional logic