# BRE Quantifiers
ab\?c	b	abc	abc
ab\+c	b	abc	abc
# BRE Branching
abc\|de	b	abc	abc
a\|b\|c	b	abc	a
\(ab\|bc\)	b	abcd	ab
# ERE Backrefs
(ab)\1	-	ab
(ab)\1	-	abab	abab
\1(ab)	C	ESUBREG
(a)(b)(c)(d)(e)(f)(g)(h)(i)\9	-	abcdefghii	abcdefghii
# \w, \W, \s, \S (alnum, ^alnum, space, ^space)
\w+	-	-%@a0X-	a0X
\w\+	b	-%@a0X-	a0X
\s+	-	aSNTb	SNT
\s\+	b	aSNTb	SNT
# Word boundaries (\b, \B, \<, \>, \`, \')
# (is/not boundary, start/end word, start/end subject string)
\babc\b	&	<abc>	abc
\<abc\> &	<abc>	abc
\Babc\B	&	abc
\B[abc]\B	&	<abc>	b
\B[abc]+	-	<abc>	bc
\B[abc]\+	b	<abc>	bc
\`abc	&	abc	abc
abc\'	&	abc	abc
\`abc\'	&	abc	abc
\`.+\'	-	abNc	abNc
\`.\+\'	b	abNc	abNc
(\`a)	-	Na
(a\`)	-	aN
(a\')	-	aN
(\'a)	-	Na