ok 1 - to pass # TODO STRINGIFICATION
#      quality: 0.33
not ok 2 - to fail # TODO STRINGIFICATION
#   Failed (TODO) test 'to fail'
#   at /home/lanx/perl/pm/test_rank.pl line 10.
#          got: 'a--b'
#     expected: 'a+(-b)', 'a+-b', 'a-b'
#      quality: 0.00
1..2