anchor.diff:  	   oneof([
              {unop, fun erlang:binary_to_list/1,  smaller_tree(binary)},
   	   {unop, fun erlang:integer_to_list/1, smaller_tree(integer)},
  -	   {unop, fun erlang:float_to_list/1,   smaller_tree(float)},
  +%Erlang version isn't too reliable on last digits   {unop, fun erlang:float_to_list/1,   smaller_tree(float)},
   	   {unop, fun erlang:tuple_to_list/1,   smaller_tree(tuple)},
   	   {unop, fun lists:flatten/1,          smaller_tree(list)},
   	   {binop, oneof([fun erlang:'++'/2, fun erlang:'--'/2]),
   	    smaller_tree(list), smaller_tree(list)},
  -	   {binop, fun erlang:integer_to_list/1,
  +	   {binop, fun erlang:integer_to_list/2,
   	    smaller_tree(integer), smaller_tree(integer)}
   	   ])]);
   program_tree(binary) ->
  
positive.code: program_tree(number) ->
      smaller_tree(oneof([integer, float]));
  program_tree(iolist) ->
      oneof([list(int()),
  	   smaller_tree(binary),
  	   [smaller_tree(iolist) | smaller_tree(iolist)]
  	  ]);
  
negative.code: 	   oneof([
  	   {unop, fun erlang:term_to_binary/1,  smaller_tree(term)},
  	   {unop, fun erlang:list_to_binary/1,  smaller_tree(list)},
  %NotImplemented:	   {unop, fun erlang:atom_to_binary/1,  smaller_tree(atom)},
  %NotImplemented:	   {unop, fun lists:iolist_to_binary/1, smaller_tree(iolist)},
  	   {unop, fun erlang:'md5'/1,           smaller_tree(iolist)}
  		 ])]);
  