Obtain help on the XSPEC commands, their syntax, and examples of their use.
XSPEC> help [<topic list>]
The help command uses the XHELP interactive help facility. The optional
topic list can be used to go directly to a particular topic and sub-topic.
The X HELP facility has a number of special input characters used to access
different sub-topics. The string ¸?? will produce a summary of these
sub-topics.
To exit back to XSPEC, use an <EOF> or type <CR> until you leave the help
facility.