"on" | "off" | "redirect" 
Sets the status of the PROG prompt. The default is "on", i.e. PROG
prompts for the next command by writing "discus > ". You can turn this
prompt off. This is useful, if you are running a long macro and do not
want to get all the prompts written into the output. By using this
option you can considerably shorten the output written by PROG into a
redirected log file. If you are using PROG on a UNIX platform, you can
start the program with redirected input by the command:
"prog < inputfile"By default, PROG will write the prompt "discus >" into the outputfile, expecting a RETURN from the keyboard. Very long lines in the output file will result. To avoid this situation insert the line "set output,redirect" as first line in the inputfile to force discus to echo the lines from file inputfile.
set error , "cont" | "exit"
Sets the error status.
"cont" PROG returns the normal prompt after the display of the error
message. You can continue the input of commands.
"exit" PROG terminates after the display of the error message.
This option is useful if you run PROG in the batch mode of your
operating system. Instead of continuing with a faulty calculation
PROG stops and you can immediately check the error.
set debug, "on" | "off"
This command allws the user to enable various DEBUG outputs ...