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author | Kaz Kylheku <kaz@kylheku.com> | 2010-01-16 08:20:48 -0800 |
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committer | Kaz Kylheku <kaz@kylheku.com> | 2010-01-16 08:20:48 -0800 |
commit | 492962468b6764a903ecba3d5cd2ed6751aed3ab (patch) | |
tree | bda7ac2ec1425b8e7db2c25e301ab9aee721f379 | |
parent | 036050a7914dbc3af84202dfc7d515c3c62c2de9 (diff) | |
download | txr-492962468b6764a903ecba3d5cd2ed6751aed3ab.tar.gz txr-492962468b6764a903ecba3d5cd2ed6751aed3ab.tar.bz2 txr-492962468b6764a903ecba3d5cd2ed6751aed3ab.zip |
Grammar.
-rw-r--r-- | txr.1 | 8 |
1 files changed, 4 insertions, 4 deletions
@@ -2883,12 +2883,12 @@ in mind this relationship between regular expressions and sets in understanding intersection and complement. Given a finite set of strings, like the set { "abc", "def" }, which corresponds -to the regular expression (abc|def), the complement is set which contains an -infinite number of strings: it consists of all possible strings except "abc" +to the regular expression (abc|def), the complement is the set which contains +an infinite number of strings: it consists of all possible strings except "abc" and "def". It includes the empty string, all strings of length 1, all strings of length 2, all strings of length 3 other than "abc" and "def", all strings of -length 4, etc. This means that a "harmless looking" expression like -~(abc|def) can actually match arbitrarily long inputs. +length 4, etc. This means that a "harmless looking" expression like ~(abc|def) +can actually match arbitrarily long inputs. .SS Set Difference |