anchor.diff:  %% @see erl_parse
   %% @see get_ctxt_precedence/1
   
  -set_ctxt_precedence(Ctxt, Prec) ->
  -    set_prec(Ctxt, Prec).
  -
  -set_prec(Ctxt, Prec) ->
  +
  +set_ctxt_precedence(Ctxt,Prec) -> set_prec(Ctxt,Prec).
  +
  +set_prec(Ctxt,Prec) ->
       Ctxt#ctxt{prec = Prec}.    % used internally
   
  +
   reset_prec(Ctxt) ->
  -    set_prec(Ctxt, 0).    % used internally
  +    set_prec(Ctxt,0).    % used internally
  +
   
   %% @spec (context()) -> integer()
   %% @doc Returns the paper widh field of the prettyprinter context.
   %% @see set_ctxt_paperwidth/2
   
  -get_ctxt_paperwidth(Ctxt) ->
  -    Ctxt#ctxt.paper.
  +
  +get_ctxt_paperwidth(Ctxt) -> Ctxt#ctxt.paper.
   
   %% @spec (context(), integer()) -> context()
   %%
  
positive.code: %% @see format/2
  %% @see prettypr:best/2
  
  best(Node, Options) ->
      W = proplists:get_value(paper, Options, ?PAPER),
      L = proplists:get_value(ribbon, Options, ?RIBBON),
      prettypr:best(layout(Node, Options), W, L).
  
  
  %% =====================================================================
  %% @spec layout(Tree::syntaxTree()) -> document()
  %% @equiv layout(Tree, [])
  
  layout(Node) ->
      layout(Node, []).
  
  
  %% =====================================================================
  %% @spec layout(Tree::syntaxTree(), Options::[term()]) -> document()
  
negative.code: %%
  %% @see get_ctxt_paperwidth/1
  
  
  set_ctxt_paperwidth(Ctxt,W) -> Ctxt#ctxt{paper = W}.
  
  %% @spec (context()) -> integer()
  %% @doc Returns the line widh field of the prettyprinter context.
  %% @see set_ctxt_linewidth/2
  
  
  get_ctxt_linewidth(Ctxt) -> Ctxt#ctxt.ribbon.
  
  %% @spec (context(), integer()) -> context()
  %%
  