Goal: Use Gunther Rademacher’s REx Parser Generator (https://www.bottlecaps.de/rex/) to create a parser for XPath 3.1.
Input: XPath 3.1 EBNF file supplied at https://www.bottlecaps.de/rex/xpath-31.ebnf.
Settings: xpath-31.txt -backtrack -xslt -tree -name xpath3.1_parser