Changing predicate to complement or negative and negating the statement can make new statements {obverse}|. Obversions of the four categorical forms are valid. All A are B, so Not (All A are not B). Some A are B, so Not (Some A are not B). Some A are not B, so Not (Some A are B). No A are B, so Not (No A are not B). If converse is true, obverse is true.
Mathematical Sciences>Logic>Statements>Permutations
3-Logic-Statements-Permutations
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Date Modified: 2022.0224