Loading a whole index as a 2D array implies that all the spectra are
consistent (basically the same coordinate system and the same frequency
axis) to obtain meaningful results. A new command, named
LAS\CONSISTENCY, was introduced to check the consistency of all the
spectra of the current index. The source name, the source position, the
line name and the frequency axis are checked by default. It is possible to
avoid one or several of those checks with the NOCHECK option. The
commands which work on the whole index (e.g. LOAD or
TABLE) automatically trigger the check of the index consistency,
if this check was not already done previously.