anchor.diff:      F = {function,0,Name,A,[{clause,0,Args,[],Body}]},
       NA = {Name,A},
       {[F|Fs],St#expand{exports=add_element(NA, St#expand.exports),
  -		      defined=add_element(NA, St#expand.defined)}}.
  +		      defined=gb_sets:add_element(NA, St#expand.defined)}}.
   
   %% define_function(Form, State) -> State.
   %%  Add function to defined if form is a function.
  
positive.code:                  compile=[],                    %Compile flags
                   attributes=[],                 %Attributes
                   callbacks=[],                  %Callbacks
                   defined=[],                    %Defined functions
                   vcount=0,                      %Variable counter
                   func=[],                       %Current function
                   arity=[],                      %Arity for current function
  
negative.code:     {Efs,St2} = expand_pmod(Tfs, St1),
      %% Get the correct list of exported functions.
      Exports = case member(export_all, St2#expand.compile) of
                    true -> gb_sets:to_list(St2#expand.defined);
                    false -> St2#expand.exports
                end,
      %% Generate all functions from stored info.
  