Rule-based Web site verification

Denotation of Web sites

• In this framework, we assume a Web page to be a well-formed XML document, since there are plenty of programs and online services that are able to validate XML syntax and perform link checking. Since XML documents are provided with a tree-like structure, they can be straightforwardly encoded as ground Herbrand terms of a given term algebra ז (Text U Tag), where Text represents the set of all the finite strings over a given alphabet and Tag is a set of tag symbols ABF06. Note that XML tag attributes can be considered as common tagged elements, and hence be translated analogously. Therefore, a Web site can be seen as a finite set of ground terms belonging to ז (Text U Tag). In the following, we will also consider terms of the non-ground term algebra ז (Text U Tag , V), which may contain variables. An element s ε ז (Text U Tag , V) is called XML document template. In our methodology, Web page templates are used to specify properties of Web sites.