In
mathematics, a
reflexive relation is a
binary relation on a set for which every element is related to itself. In other words, a relation ~ on a set
S is reflexive when
x ~
x holds true for every
x in
S, formally: when ∀
x∈
S:
x~
x holds. An example of a reflexive relation is the relation "
is equal to" on the set of
real numbers, since every real number is equal to itself. A reflexive relation is said to have the
reflexive property or is said to possess
reflexivity.