Types for Xcerpt

Here you can try out an Xcerpt prototype together with a prototype of a descriptive type system.
There are examples of queries below which demonstrate usage of the type system.
To see how it works you need to choose a variant of a query.
You will be then redirected to another web page where you need to press the button 'Type program'.

Query examples

Query	Variant	Description
Q1	Q1a	Query correct wrt. a given type specification
	Q1b	Inferred result type is empty because of a typo in the query: "popa" instead of "pop"
	Q1c	Query incorrect wrt. a given type specification. The variable TITLE should be restricted in the query.
	Q1d	No type specification given. Only type inference performed.
Q2	Q2	Type specification given by DTD.
mQ	mQ	Multiple query rules program