# Reflexive relation

In mathematics, a binary relation *R* on a set *X* is **reflexive** if it relates every element of *X* to itself.[1][2]

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indicates that the column's property is required by the definition of the row's term (at the very left). For example, the definition of an equivalence relation requires it to be symmetric. ✗ indicates that the property may, or may not hold. All definitions tacitly require the homogeneous relation be transitive: for all if and then and there are additional properties that a homogeneous relation may satisfy. |

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**. Along with symmetry and transitivity, reflexivity is one of three properties defining equivalence relations.