(A(A|B(*ACCEPT)|C)D)(E) AB y $1 AB
(A(A|B(*ACCEPT)|C)D)(E) ACDE y $1$2$3 ACDCE
+(a)(?:(?-1)|(?+1))(b) aab y $&-$1-$2 aab-a-b
+(a)(?:(?-1)|(?+1))(b) abb y $1-$2 a-b
+(a)(?:(?-1)|(?+1))(b) acb n - -
+
+(foo)(\R1) foofoo y $1-$2 foo-foo
+(foo)(\R1)(foo)(\R1) foofoofoofoo y $1-$2-$3-$4 foo-foo-foo-foo