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

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

  ? {[def x := thunk {}, x]} :DeepPassByCopy
  # problem: [<_>, <_>] is not DeepPassByCopy because <_> is not