I'm working on a machine learning project, to evolve building designs based on some user-defined success criteria. I'd like to persist intermediate results as a CGA ruleset, then use those as inputs to subsequent generations. Is there some formal, BNF-Like (or Yacc, or ANTLR, or whatever) definition for CGA grammar, other than the very helpful (but not very formal) CGA Reference Index ?
Your project sounds very interesting. Regrettably the CGA grammar definition can not be published to external users.
Of course you can use the CGA reference to derive your own version.