identity relation
A mathematical term for a relation where every element is related only to itself. Used in set theory and logic.
The identity relation on set A is such that each element is related only to itself.
恒等写像 (identity mapping/function) is a function that maps each element to itself, while 恒等関係 is a relation (a set of ordered pairs) with the same property.
Compound of 恒等 (identity, equality) and 関係 (relation). A technical term in mathematics.