anchor.diff:  	      | c_module() | c_primop() | c_receive() | c_seq()
                 | c_try()    | c_tuple()  | c_values()  | c_var().
   
  +-type var_name() :: integer() | atom() | {atom(), integer()}.
  +
   %% =====================================================================
   %% Representation (general)
   %%
  
positive.code: %%    <td>call</td>
  %%    <td>case</td>
  %%    <td>catch</td>
  %%  </tr><tr>
  %%    <td>clause</td>
  %%    <td>cons</td>
  %%    <td>fun</td>
  %%    <td>let</td>
  %%    <td>letrec</td>
  %%    <td>literal</td>
  %%    <td>module</td>
  %%  </tr><tr>
  %%    <td>primop</td>
  
negative.code:     %% we get exactly one element, we generate a 'c_cons' call
      %% instead of 'make_list' to reconstruct the node.
      case split_list(Node) of
  	{[H], Node1} ->
  	    meta_call(c_cons, [meta(H), meta(Node1)]);
  	{L, Node1} ->
  	    meta_call(make_list,
  		      [make_list(meta_list(L)), meta(Node1)])
  