From: "bryan rasmussen" <rasmussen.bryan@xxxxxxxxx>
I think people have forgotten the explicit reference Roger made to
schematron, since schematron is a validation technology that can be
implemented in XSL-T it follows that the expression
matches(flt:Aircraft/flt:Altitude, '[0-9]+')
would give you the same capabilities as XML Schema datatype checking
in any actually useful scenario.

That said, this would only apply to ISO Schematron with the binding
language set to xpath 2.0