The cascade element
The cascade element groups a set of regular expression transforms that are applied to either the user input text or the generated paraphrases. The DTD definition is:
<!ELEMENT cascade (pre|post|response)*> <!ATTLIST cascade alive CDATA #IMPLIED description CDATA #IMPLIED>
Here is an example cascade from geo.cphrase
<cascade> <response from="governor" to="there is no information on politicians"/> <pre from="of the us" to=""/> <pre from="name the" to="what"/> <pre from="name all" to="what"/> <pre from="state the" to="what"/> <pre from="whats" to="what"/> <pre from="major cities" to="cities population over 500000"/> <pre from="big cities" to="cities"/> <pre from="rivers in" to="rivers flowing through"/> <pre from="river in" to="river flowing through"/> ... </cascade>