causaldag.classes.dag.DAG.reversible_arcs¶

DAG.reversible_arcs() → Set[Tuple[Hashable, Hashable]][source]¶

Get all reversible (aka covered) arcs in the DAG.

Returns:	Return all reversible (aka covered) arcs in the DAG. An arc i -> j is covered if the $Pa(j) = Pa(i) \cup {i}$ . Reversing a reversible arc results in a DAG in the same Markov equivalence class.
Return type:	Set[arc]

Example

>>> import causaldag as cd
>>> g = cd.DAG(arcs={(1, 2), (1, 3), (2, 3)})
>>> g.reversible_arcs()
{(1, 2), (2, 3)}