Is it idiomatic to use featurec to "destructure" values from deeply nested data structures to "store" them in lvars so they can be used in other goals?

@branch14 I don't think there are many well-developed idioms in core.logic programming. In my experience I found it better to avoid maps inside of the core.logic part of my programs, and instead translating to/from relations on the edges, but do whatever works for you.