int  initSGML(char ***mime_types, int *nrtypes, float **prefs);
  int  openSGML(const W3ADocumentInfo doc,  Widget  workarea, long id);
  int  infoSGML(long id, W3ADocumentInfo *info);
 int writeSGML(long id, const char *buf, size_t nbytes);
  int  closeSGML(long id);
 void eventSGML(long id, long source, long eventtype, void *params);