(.using
  [library
   [lux "*"
    ["_" test {"+" Test}]
    [data
     ["[0]" text]
     [collection
      ["[0]" list]
      ["[0]" set {"+" Set}]]]
    [math
     [number
      ["n" nat]]]]]
  [\\library
   ["[0]" /]])

(with_expansions [<targets> (as_is /.old
                                   /.js
                                   /.jvm
                                   /.lua
                                   /.python
                                   /.ruby
                                   /.common_lisp
                                   /.php
                                   /.r
                                   /.scheme)]
  (def: all
    (List /.Target)
    (list <targets>))
  
  (def: unique
    (Set /.Target)
    (set.of_list text.hash ..all))

  (def: verdict
    (n.= (list.size ..all)
         (set.size ..unique)))

  (def: .public test
    Test
    (<| (_.covering /._)
        (_.for [/.Target])
        ($_ _.and
            (_.cover [<targets>]
                     ..verdict)
            )))
  )