This directory contains grammar files in Bison and Wisent, used to generate the parser data in the lisp/semantic/bovine/ and lisp/semantic/wisent/ directories. You can run the parser generators with emacs -batch -Q -l semantic/bovine/grammar -f bovine-make-parsers emacs -batch -Q -l semantic/wisent/grammar -f wisent-make-parsers Currently, the parser files in lisp/ are not generated directly from these grammar files when making Emacs. This state of affairs, and the contents of this directory, will change in a future version of Emacs.