24june2019 paper1 Q20
- Option : B
- Explanation : Two propositions are contradictory, if one
of them is a denial of another. They cannot
both be true, and cannot both be false. They
have same subjects and predicates but are
different in quantities (all, some, no) as well
as qualities.
Two propositions are contrary, if they cannot both be true, but they might both be false. They have same subjects and predicates; and, are different in qualities but have the same universal quantities.
A superaltern is a universal proposition that is the basis for the immediate inference of a corresponding particular proposition.
A proposition is a subaltern of another if it must be true in case its superaltern is true, and its superaltern must be false in case the subaltern is false.
