After declaring a variable, you can assign it a value using the <assign> element, and you can reference variables in cond and expr attributes of various elements. Because VoiceXML is an XML-based application, you must use escape sequences to specify relational operators (such as greater than, less than, etc.). Table 1 lists the escape sequences.
| Relational operator | Escape sequence |
|---|---|
| < | < |
| > | > |
| <= | <= |
| >= | >= |
| & | & |
| && | && |