In a comment Fred asked why we think the EFP structure is a directed multigraph, rather than just a simple digraph. The answer is because we allow self-loops and multiple parallel edges. We'll give linguistic examples later, but in the meantime, here's a fun "blast from the past".
In the book Rules, constraints, and phonological phenomena edited by Bert Vaux and Andrew Nevins, we had a chapter where we discussed various aspects of reduplication. One non-linguistic case that we found quite striking was Jeanne Bamberger's discussion of children's tune-building with Montessori bells in chapter 7 of The Mind Behind the Musical Ear.
Here's the tune for "Hot Cross Buns" in standard musical notation:
And here's our reinterpretation of the child's encoding of the tune using events, features and precedence, following Bamberger's discussion quite closely:
Bamberger's chapter makes for very interesting reading because the Montessori bells have particular physical characteristics that she is able to creatively employ to interpret the children's tune-building in very insightful ways. Unlike a piano, there are multiple bells with the same pitch. And the bells themselves are all the same size, so you cannot tell the relative pitch of the bells by visual inspection, you must strike them and hear the note. The bells were deliberately designed in this way, and are part of the Montessori sensorial materials. This allowed Bamberger to make interesting observations about which notes the children felt were the "same" or "different". For instance, the two separate "C" events in our diagram were executed on separate bells, and the same is true for the two "D" events.
