a ( b ( x ) c ) d
a (___________) d
a (___________) d
a (___________) d
a _____________ d
a _____________ d
a _____________ d
a { b { x } c } d
a {___________} d
a {___________} d
a {___________} d
a _____________ d
a _____________ d
a _____________ d
a [ b [ x ] c ] d
a [___________] d
a [___________] d
a _____________ d
a _____________ d
a < b < x > c > d
a <___________> d
a <___________> d
a _____________ d
a _____________ d
a <a> b <b> x </b> c </a> d
a <a>________________</a> d
a _______________________ d