XML Serialization Annotation This rule has the following XML serialization annotation: [ localname = "Or" children = ( formula*3 ) ] This means that a Formula derived through this rule will be serialized thus: <Or> <formula*> XML serialization of the 3rd RHS symbol (Formulas_opt) </formula*> </Or> N.B.: an XML construct such as <formula*>...</formula*> stands for either zero, one, or many occurrences of <formula>...</formula>. distributed over the element's contents (the "..."), which, accordingly, may be either empty, a single XML element, or a list thereof.