anchor.diff:  	Is -> find_fixpoint(OptFun, Is)
       end.
   
  -opt([{test,_,{f,L}=Lbl,_}=I|[{jump,{f,L}}|_]=Is], Acc0, St0) ->
  +opt([{test,_,{f,L}=Lbl,_}=I|[{jump,{f,L}}|_]=Is], Acc, St) ->
       %% We have
       %%    Test Label Ops
       %%    jump Label
  
positive.code: %%% on the program state.
  %%% 
  
  -import(lists, [dropwhile/2,foldl/3,mapfoldl/3,reverse/1,reverse/2]).
  
  -type instruction() :: beam_utils:instruction().
  
  
negative.code: normalize_replace([], _Replace, Acc) ->
      maps:from_list(Acc).
  
  collect_labels(Is, Label, #st{entry=Entry,replace=Replace} = St) ->
      collect_labels_1(Is, Label, Entry, Replace, St).
  
  