anchor.diff:  %%      code to which Node belongs,  Node is the abstract syntax tree representaion of 
   %%      the syntax phrase of interest, and SearchPaths specifies the directories to 
   %%      search for related local Erlang source files.
  -%% @spec has_side_effect(File::filename(), Node::syntaxTree(), SearchPaths::[dirname()])-> bool()
  +%% @spec has_side_effect(File::filename(), Node::syntaxTree(), SearchPaths::[dir()])-> bool()
   
   has_side_effect(File, Node, SearchPaths) ->
       LibSideEffectFile = filename:join(?WRANGLER_DIR, "plt/side_effect_plt"),
  
positive.code: 
  
  %% =====================================================================
  %% @spec get_modules_by_file(Files::[filename()]) -> [{atom(), dirname()}]
  %% @doc The a list of files to a list of two-element tuples, with the first 
  %% element of the tuple being the module name, and the second element 
  %% binding the directory name of the file to which the module belongs.
  
negative.code: 
  %% =====================================================================
  %% @spec once_tdTU(Function, Tree::syntaxTree(), Others::[term()])-> term()
  %%       Function = (syntaxTree(), {term()}) -> term()
  %%
  %% @doc Once-topdown type-unifying traversal of the abstract syntax tree with some
  %% information collected. This function does a pre-order traversal of the
  