XPathCompiler.DeclareNamespace Method 

Declare a namespace for use by the XPath expression.

Parameters

prefix

The namespace prefix to be declared. Use a zero-length string to declare the default namespace (that is, the default namespace for elements and types).

uri

The namespace URI. It is possible to specify a zero-length string to "undeclare" a namespace.

See Also

XPathCompiler Class | Saxon.Api Namespace