Consider the following recursive DTD.
<!DOCTYPE parts [
<!ELEMENT part (name, subpartinfo*)>
<!ELEMENT subpartinfo (part, quantity)>
<!ELEMENT name ( #PCDATA )>
<!ELEMENT quantity ( #PCDATA )>
a. Give a small example of data corresponding to the above DTD.
b. Show how to map this DTD to a relational schema. You can assume that part names are unique, that is, whereever a part appears, its subpart structure will be the same.