Assertion: graph's edge | /r/HasProperty | unidirectional
Facets:
Source sentences:
text: This just means that each edge in the graph is unidirectional, i.e., it goes from one vertex to another.
text: We can imagine that the edges are unidirectional since trains are only allowed to go in one direction on the tracks (a new government rule so trains don't crash into each other any more).