In this directory everything can be removed except some files needed to build a .chm :

   hh_do_hhc_hhk    a script to create hh-gprolog.hhc (toc) hh-gprolog.hhk (index)
   hh-mkind.tex     used by the script to create .hhc
   hh-mktoc.tex     used by the script to create .hhk

   hh-gprolog.hhp   a HTMLHelp project to build the .chm

