arithexp.dtd

java web 开发,Java Xml 编程指南书籍源码

<!ENTITY % exp "(num|add|sub|mul|div)">
<!ELEMENT arithexp %exp;>
<!ELEMENT add (%exp;)+>
<!ELEMENT sub (%exp;)+>
<!ELEMENT mul (%exp;)+>
<!ELEMENT div (%exp;)+>
<!ELEMENT num (#PCDATA)>