[element(bar, [], [element(foo, [], [element(a, [], [element(b, [], [x]), element(c, [], [y])]), element(a, [], [element(b, [], [x]), element(c, [], [y])]), element(a, [], [element(b, [], [x]), element(c, [], [y])]), element(a, [], [element(b, [], [x]), element(c, [], [y])])])])].