There are a bunch of direct/back link situations we can get into, including ones in the case where a note hasn’t yet been created. The pic below shows the notes and the local/global graph that covers the ones I could come up with:
I think there’s room for improvement - I think that the global graph for these notes should be:
Solid lines for linked mentions, dotted lines for unlinked mentions, and dotted node for a linked but not yet created node (which then can have unlinked mentions also connecting). Carrots as a note only has unlinked mentions currently, so there’s no dotted node for it (if we had a node for all unlinked mentions, we’d have a graph with every word we used in it, no thanks 
)
PS Local graphs (I think) should be identical to the global graph, just centered on the local node and filtered by the number of jumps - otherwise, completely the same.