anchor.diff:  		    false -> T
   		  end
   	end,
  -      ReturnType = mk_fun_var(fun(Map) ->
  +      ReturnType = ?mk_fun_var(fun(Map) ->
   				  TmpArgTypes0 = lookup_type_list(Args, Map),
   				  TmpArgTypes = [UnopaqueFun(T) || T<- TmpArgTypes0],
   				  erl_bif_types:type(M, F, A, TmpArgTypes)
  
positive.code:     binary ->
        {State1, SegTypes} = traverse_list(cerl:binary_segments(Tree),
  					 DefinedVars, State),
        Type = mk_fun_var(fun(Map) ->
  			    TmpSegTypes = lookup_type_list(SegTypes, Map),
  			    t_bitstr_concat(TmpSegTypes)
  			end, SegTypes),
        {state__store_conj(mk_var(Tree), sub, Type, State1), mk_var(Tree)};
      bitstr ->
        Size = cerl:bitstr_size(Tree),
  
negative.code: 		  end
  	      end
  	  end,
  	?mk_fun_var(F, [Dst, A])
      end,
    Arg1FunVar = ArgFun(Arg2, 2),
    Arg2FunVar = ArgFun(Arg1, 1),
  