1272343Sngie# back references, ugh 2272343Sngiea\(b\)\2c bC ESUBREG 3272343Sngiea\(b\1\)c bC ESUBREG 4272343Sngiea\(b*\)c\1d b abbcbbd abbcbbd bb 5272343Sngiea\(b*\)c\1d b abbcbd 6272343Sngiea\(b*\)c\1d b abbcbbbd 7272343Sngie^\(.\)\1 b abc 8272343Sngiea\([bc]\)\1d b abcdabbd abbd b 9272343Sngiea\(\([bc]\)\2\)*d b abbccd abbccd 10272343Sngiea\(\([bc]\)\2\)*d b abbcbd 11272343Sngie# actually, this next one probably ought to fail, but the spec is unclear 12272343Sngiea\(\(b\)*\2\)*d b abbbd abbbd 13272343Sngie# here is a case that no NFA implementation does right 14272343Sngie\(ab*\)[ab]*\1 b ababaaa ababaaa a 15272343Sngie# check out normal matching in the presence of back refs 16272343Sngie\(a\)\1bcd b aabcd aabcd 17272343Sngie\(a\)\1bc*d b aabcd aabcd 18272343Sngie\(a\)\1bc*d b aabd aabd 19272343Sngie\(a\)\1bc*d b aabcccd aabcccd 20272343Sngie\(a\)\1bc*[ce]d b aabcccd aabcccd 21272343Sngie^\(a\)\1b\(c\)*cd$ b aabcccd aabcccd 22