Can ANTLR grammar files be modularised?

I am building ANTLR3 applications where some of the same grammar rules are likely to be used in different applications. There will be many *.g files but they may, for example, all wish to reference the same version of FLOAT. Are there "import" facilities whereby a *.g can be assembled from other *.g fi开发者_JAVA技巧les and if so what are the precedence rules?

You mean composite grammars?