to itself is a coreflexive relation. The equality relation is the only example of a both reflexive and coreflexive relation, and any coreflexive relation is a subset of the identity relation.; [[Left quasi-reflexive]] : for all , if then .; [[Right quasi-reflexive]] : for all , if then .; [[Quasi-reflexive relation : for all , if then and . A relation is quasi-reflexive if, and only if, it is both left and right quasi-reflexive.

The previous 6 alternatives are far from being exhaustive; e.g., the binary relation defined by is neither