is the least reflexive binary relation
Reflexive: for all x in X, xRx. Least?
[Reflexive relation
- Wikipedia](https://en.wikipedia.org/wiki/Reflexive_relation)
The reflexive closure ≃ of a binary relation ~ on a set X is the smallest reflexive relation on X that is a superset of
. Equivalently, it is the union of ~ and the identity relation on X, formally: (≃) = () ∪ (=). For example, the reflexive closure of (<) is (≤).
largest relation between session types coinductively defined