(set spam 1)
  (def myfun (x) (prn x))

  ;; Uses 'a'
  (use 'a)
  (a@myfun "hi!")

  ;; Uses all in 'a'
  (use* 'a)
  (myfun "hy!")

  ;; Use 'a' as 'z'
  (useas 'z 'a)
  (z@myfun "ho!")

  arc> (use 'a)
  t
  arc> a@spam
  1
  arc> (set a@spam 5)
  5
  arc> (use 'a)
  t
  arc> a@spam
  5
  arc> (use 'd)
  ho!
  t
  arc> (use 'b)
  hi!
  t