See instead:
- https://edu.visl.dk/constraint_grammar.html
- https://edu.visl.dk/cg3.html
- https://edu.visl.dk/cg3/chunked/
- manual/
- https://groups.google.com/group/constraint-grammar

Other links:
- https://en.wikipedia.org/wiki/Constraint_Grammar
- https://wiki.apertium.org/wiki/Constraint_Grammar
