(.module:
  [lux (#- Type)
   [abstract
    [equivalence (#+ Equivalence)]
    [hash (#+ Hash)]]
   [data
    ["." product]
    ["." text
     ["%" format (#+ format)]]]]
  ["." // #_
   ["#" artifact (#+ Artifact)
    [type (#+ Type)]]])

(type: #export Dependency
  {#artifact Artifact
   #type Type})

(def: #export hash
  (Hash Dependency)
  ($_ product.hash
      //.hash
      text.hash
      ))

(def: #export equivalence
  (Equivalence Dependency)
  (\ hash &equivalence))