/
(?(DEFINE)(?<namepart>\w+))(?(DEFINE)(?<name>(?&namepart)(\.(?&namepart))*))(?(DEFINE)(?<helper>(?<hexpr>(?&sexpr))\|(?<hname>(?&namepart))))(?(DEFINE)(?<sexpr>(?&name)|\((?&expr)\)))(?(DEFINE)(?<expr>((?&or)|(?&helper))))(?(DEFINE)(?<or>(?<or1>(?&name))\|\|(?<or2>(?&expr))?))(?&or)
/
x