FIND

        LAS\FIND [APPEND|NEW_DATA|UPDATE] [Options]

    FIND performs a search in the input file to build a new index, according
    to  selection criteria defined by the SET command. These criteria may be
    temporarily modified by the following options.

    Observation numbers:
      /ALL                  all versions of each observations are searched for
                            (if not present: only the last version)
      /NUMBER n1 n2         search for the specified range of observation number
      /ENTRY  n1 n2         search for the specified range of entry numbers

    General information:
      /SCAN s1 s2           search for the specified range of scan numbers
      /SUBSCAN s1 s2        search for the specified range of subscan numbers
      /TELESCOPE name       search for the telescope used
      /OBSERVED d1 d2       search for these observation dates (JJ-MMM-YYYY)
      /REDUCED d1 d2        search for these reduction dates (JJ-MMM-YYYY)
      /QUALITY q            search for the data of quality better than Q
      /SECTION name         search for observations which have this section defi

    Spectroscopic information:
      /LINE name            search by line name
      /FREQUENCY f1 f2      search by signal or image frequency value or range

    Position information:
      /SOURCE name          search by source name
      /OFFSET a1 a2 [unit]  search for this position (within SET MATCH tolerance
      /RANGE w e s n [unit] search for the specified range of offsets (plus SET
      /POSITION a0 d0 sys   search for observations by absolute position
      /MASK File            search for observations in the mask

    FIND does not return an error if the index is empty,  but  the  variable
    FOUND  is set to 0. FOUND is always set to the number of observations in
    the index.