# Copyright 2005-2007 Kevin Reid, under the terms of the MIT X license
# found at http://www.opensource.org/licenses/mit-license.html ................

  ? Data
  # value: <Data>
  
  ? 1 :Data
  # value: 1
  
  ? fn {} :Data
  # problem: <__main$_> is not Data because <__main$_> is not
  
  ? [1] :Data
  # value: [1]
  
  ? [fn {}] :Data
  # problem: [<__main$_>] is not Data because <__main$_> is not
  
  ? {def x := [1, x, 2]} :Data
  # value: [1, <***CYCLE***>, 2]
  
  ? {def x := [1, x, fn {}]} :Data
  # problem: [1, <***CYCLE***>, <__main$_>] is not Data because <__main$_> is not

  ? {[def x := fn {}, x]} :Data
  # problem: [<__main$_>, <__main$_>] is not Data because <__main$_> is not
  
  ? <shared> :Data
  # value: <shared:*>
  
  x ? e`1 + 1` :Data
  x # value: e`1 + 1`