(.module:
  [library
   [lux "*"
    [abstract
     [equivalence {"+" [Equivalence]}]]
    [data
     ["[0]" sum]
     ["[0]" text]]
    [world
     [file {"+" [Path]}]
     [net {"+" [URL]}]]]])

(type: .public Origin
  (Variant
   {#Local Path}
   {#Remote URL}))

(def: .public equivalence
  (Equivalence Origin)
  ($_ sum.equivalence
      text.equivalence
      text.equivalence
      ))