Description

   Use the LBR$FIND routine to access a module that you had accessed
   earlier in your program. For example, if you look up several
   keys with LBR$LOOKUP_KEY, you can save the RFAs returned by
   LBR$LOOKUP_KEY and later use LBR$FIND to reaccess the modules.
   Thus, you do not have to look up the module header's key every
   time you want to access the module. If the specified RFA is
   valid, LBR$FIND initializes internal tables so you can read the
   associated data.