anchor.diff:  
   'subst-if'(New, Test, Tree) ->
       case Test(Tree) of
  -    true -> New;
  -    false ->
  -        case Tree of
  -        [H|T] ->
  -            ['subst-if'(New, Test, H)|'subst-if'(New, Test, T)];
  -        _ -> Tree
  -        end
  +        true -> New;
  +        false ->
  +            case Tree of
  +                [H|T] ->
  +                    ['subst-if'(New, Test, H)|'subst-if'(New, Test, T)];
  +                _ -> Tree
  +            end
       end.
   
   %% subst-if-not(New, Test, Tree) -> Tree.
   
   'subst-if-not'(New, Test, Tree) ->
       case Test(Tree) of
  -    false -> New;
  -    true ->
  -        case Tree of
  -        [H|T] ->
  -            ['subst-if-not'(New, Test, H)|'subst-if-not'(New, Test, T)];
  -        _ -> Tree
  -        end
  +        false -> New;
  +        true ->
  +            case Tree of
  +                [H|T] ->
  +                    ['subst-if-not'(New, Test, H)|'subst-if-not'(New, Test, T)];
  +                _ -> Tree
  +            end
       end.
   
   %% sublis(AList, Tree) -> Tree.
   
   sublis(Alist, Tree) ->
       case assoc(Tree, Alist) of
  -    [_|New] -> New;                         %Found it
  -    [] ->                                   %Not there
  -        case Tree of
  -        [H|T] ->
  -            [sublis(Alist, H)|sublis(Alist, T)];
  -        _ -> Tree
  -        end
  +        [_|New] -> New;                         %Found it
  +        [] ->                                   %Not there
  +            case Tree of
  +                [H|T] ->
  +                    [sublis(Alist, H)|sublis(Alist, T)];
  +                _ -> Tree
  +            end
       end.
   
   eval(Sexpr) -> eval(Sexpr, lfe_env:new()).  %Empty environment.
  
positive.code: 
  format_stacktrace(St0, Skip, Format) ->
      St1 = reverse(dropwhile(Skip, reverse(St0))),
      Print = fun ({M,F,A}) when is_integer(A) ->    %Pre R15
              lfe_io:format1("  in (~w ~w ~w)\n", [M,F,A]);
          ({M,F,A}) -> ["  in ",Format([':',M,F|A], 5),"\n"];
          %% R15 and later.
          ({M,F,A,_}) when is_integer(A) ->
              lfe_io:format1("  in (~w ~w ~w)\n", [M,F,A]);
          ({M,F,A,_}) -> ["  in ",Format([':',M,F|A], 5),"\n"]
      end,
      map(Print, St1).
  
negative.code: %%  exception; SkipFun is used to trim the end of stack; FormatFun is
  %%  used to format terms; and Indentation is the current column.
  
  format_exception(Cl, Error0, St0, Sf, Ff, I) ->
      Cs = case Cl of                         %Class type as string
               throw -> "throw";
               exit -> "exit";
               error -> "error"
           end,
      {Error1,St1} = case is_stacktrace(St0) of
                         true -> {Error0,St0};
                         false -> {{Error0,St0},[]}
                     end,
      P = "exception " ++ Cs ++ ": ",         %Class description string
      [P,lfe_io:prettyprint1(Error1, 10, length(P)+I-1),"\n",
       format_stacktrace(St1, Sf, Ff)].
  
  %% format_stacktrace(Stacktrace, SkipFun, FormatFun) -> DeepCharList.
  %%  Format a stacktrace. SkipFun is used to trim the end of stack;
  