1# back references, ugh
2a\(b\)\2c	bC	ESUBREG
3a\(b\1\)c	bC	ESUBREG
4a\(b*\)c\1d	b	abbcbbd	abbcbbd	bb
5a\(b*\)c\1d	b	abbcbd
6a\(b*\)c\1d	b	abbcbbbd
7^\(.\)\1	b	abc
8a\([bc]\)\1d	b	abcdabbd	abbd	b
9a\(\([bc]\)\2\)*d	b	abbccd	abbccd
10a\(\([bc]\)\2\)*d	b	abbcbd
11# actually, this next one probably ought to fail, but the spec is unclear
12a\(\(b\)*\2\)*d		b	abbbd	abbbd
13# here is a case that no NFA implementation does right
14\(ab*\)[ab]*\1	b	ababaaa	ababaaa	a
15# check out normal matching in the presence of back refs
16\(a\)\1bcd	b	aabcd	aabcd
17\(a\)\1bc*d	b	aabcd	aabcd
18\(a\)\1bc*d	b	aabd	aabd
19\(a\)\1bc*d	b	aabcccd	aabcccd
20\(a\)\1bc*[ce]d	b	aabcccd	aabcccd
21^\(a\)\1b\(c\)*cd$	b	aabcccd	aabcccd
22