Some Essential Predicates

We have already seen numerical predicates: ancestor::div[1], //div/p[3], list/item[12]
- Numbers as predicates allow you to search for the Nth node along an axis
- Nodes closer to the context node have lower numbers
Axes (e.g., descendant::, parent::, and ancestor::) can be used in predicates
- preceding::pb[1]/@n — what page number am I on?
- //div[descendant::persName] — searches for divisions that have a descendant <persName>
  — what you get back is a sequence of <div>s
- (as opposed to //div//persName, which searches for the <persName> elements that are descendants of <div>
  — what you get back is a sequence of <persName>s)

Schematron in ODD slide 23 of 39