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: 
  'rassoc-if'(Pred, [[_|V]=Pair|L]) ->
      case Pred(V) of
      true -> Pair;
      false -> 'rassoc-if'(Pred, L)
      end;
  'rassoc-if'(_, []) -> [].
  
  'rassoc-if-not'(Pred, [[_|V]=Pair|L]) ->
      case Pred(V) of
      false -> Pair;
      true -> 'rassoc-if-not'(Pred, L)
      end;
  'rassoc-if-not'(_, []) -> [].
  
  
negative.code: 
  'assoc-if'(Pred, [[K|_]=Pair|L]) ->
      case Pred(K) of
          true -> Pair;
          false -> 'assoc-if'(Pred, L)
      end;
  'assoc-if'(_, []) -> [].
  
  'assoc-if-not'(Pred, [[K|_]=Pair|L]) ->
      case Pred(K) of
          false -> Pair;
          true -> 'assoc-if-not'(Pred, L)
      end;
  'assoc-if-not'(_, []) -> [].
  
  