/** \mainpage Sphinx 3 Internals Documentation
 *
 * This manual documents the functions, files and the internal variables
 * of Sphinx 3's recognizers (both fast and slow). Currently, we intend 
 * to make it be used by Sphinx developers only.  We do not recommend
 * users to use the internal function at this point because they are
 * still quite unstable.
 *
 */