anchor.diff:          ]).
   
   %% Base Library functions implemented in this module
  --export([ car/1
  -        , caar/1
  +-export([ caar/1
           , cadr/1
           , caddr/1
  -        , cdr/1
           , cddr/1
           , cdddr/1
           , cons/2
  
positive.code: 
  'cons'(X, Y) -> [X | Y].
  
  'car'([X | _]) ->
    X.
  
  'cdr'([_ | Y]) ->
    Y.
  
  'caar'([[X | _] | _]) ->
    X.
  
  
negative.code:    , 'cons' => fun ?MODULE:cons/2
     , 'append' => fun erlang:'++'/2
     , 'reverse' => fun lists:reverse/1
     , 'car' => fun erlang:hd/1
     , 'cdr' => fun erlang:tl/1
     , 'caar' => fun ?MODULE:caar/1
     , 'cadr' => fun ?MODULE:cadr/1
     , 'cddr' => fun ?MODULE:cddr/1
  