causaldag.classes.dag.DAG.is_reversible¶

DAG.is_reversible(i: Hashable, j: Hashable) → bool[source]¶

Check if the arc i -> j is reversible (aka covered), i.e., if $pa(i) = pa(j) \setminus \{i\}$

Parameters:	i – source of the arc j – target of the arc
Returns:
Return type:	True if the arc is reversible, otherwise False.

Example

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