A function φ : X → Y between two topological spaces is continuous if and only if φ(adh A) ⊂ adh (φ A) for all A ⊂ X. This property can be extended to equivalence relations as follows. Given an equivalence relation R on X and A ⊂ X, we denote by R(A) the set of points equivalent to points in A. We can look at the property of R given by $$R\Bigl(\overline{A}\Bigr) \subset \overline{R(A)} \ \ for\ \ all\ \ A ⊂ X.$$ Is there a name for that property? Is it studied somewhere? Can it be formulated in term of the continuity of some function associated To R? I encountered this property while studying the equivalence relation associated to a foliation ("being on the same leaf").