(?|(?|(a)|(b))|(?|(c)|(d))) d y $1 d
(.)(?|(.)(.)x|(.)d)(.) abcde y $1-$2-$3-$4-$5- b-c--e--
(\N)(?|(\N)(\N)x|(\N)d)(\N) abcde y $1-$2-$3-$4-$5- b-c--e--
+(?|(?<foo>x)) x y $+{foo} x
+(?|(?<foo>x)|(?<bar>y)) x y $+{foo} x
+(?|(?<bar>y)|(?<foo>x)) x y $+{foo} x
+(?<bar>)(?|(?<foo>x)) x y $+{foo} x
+
#Bug #41492
(?(DEFINE)(?<A>(?&B)+)(?<B>a))(?&A) a y $& a
(?(DEFINE)(?<A>(?&B)+)(?<B>a))(?&A) aa y $& aa