noun
Refers to two things that form a pair or are considered together. Often used in formal or technical contexts, but can appear in everyday language.
この二つの概念は対偶をなしている。
These two concepts form a pair.
noun
A term in logic referring to the relationship between a conditional statement and its contrapositive. Used in mathematics and philosophy.
「AならばB」の対偶は「BでなければAでない」である。
The contraposition of 'if A then B' is 'if not B then not A'.