# Deep Merge Semantics are:
 - keys of objects get merged { a: .. , b: .. } with  { b: .. , c: .. }
   - the value of b needs to be merged; recurse
 - elements of arrays get
 - primitives in left and right that are distinct, produce a type error

so
 - objects have set semantics; recursive set merge
 - arrays have sequence semantics; order is important
 - certain objects produce nonsensical merge results