NullSet - Sigma Knowledge base Browser

appearance as argument number 1

(subclass NullSet Set)	Merge.kif 5636-5636	Null set is a subclass of set
(documentation NullSet EnglishLanguage "Any Set that contains no elements.")	Merge.kif 5638-5638	Null set is a subclass of set

appearance as argument number 2

(termFormat EnglishLanguage NullSet "null set")	domainEnglishFormat.kif 41426-41426
(termFormat ChineseTraditionalLanguage NullSet "空集")	domainEnglishFormat.kif 41427-41427
(termFormat ChineseLanguage NullSet "空集")	domainEnglishFormat.kif 41428-41428

antecedent

(=>
    (instance ?SET NullSet)
    (not
        (exists (?INST)
            (element ?INST ?SET))))

If X is an instance of null set, then there doesn't exist Y such that Y is an element of X