version 1.

FileSystemUsage = <file-system-usage @path string @size int>.

# This assertion publishes a dataspace that proxies assertions with
# an exception for <Observe …> which is pulsed every periodSec.
# The pulse resolution is no more than one millisecond.
Pulse = <pulse @periodSec float @proxy #:any>.

XmlTranslation = <xml-translation @xml string @pr any>.

XsltTransform = <xslt-transform @stylesheet string @input string @output any>.
XsltItems = [XsltItem ...].
XsltItem = string.