1. Consider XML data given by the following DTD:
Elements that are not defined are PCDATA.
(a) Write a XPath expression that returns all titles in the XML document
(b) Write a XQuery that returns the addresses of all theaters that have some tickets under $35 on 2010-01-01 and the titles of their show on that night.
(c) Write a XQuery that returns all concert titles whose type is chamber orchestra where the average ticket price is at least $50.
(d) Write a XQuery that based on the above XML document constructs a new XML document with the following structure: