4 Notation
This part of ISO/IEC 19757 uses XPath to identify information items in Schematron schemas.
4.2Predicate Logic
This part of ISO/IEC 19757 uses predicate logic to express the semantics of Schematron schema. The following symbols are defined for use in s6.3:
Grouping delimiters
"for all". Prefix operator.
"not". Prefix operator.
"is member of", in set operative sense. Prefix operator.
"and" (sequence). Infix operator.
"where". Such that. Infix operator.
"if and only if". Infix operator.