The command shown below isn't working.  I want the calculation to stop once the inlet pressure decays below 0 bar at the inlet.

Is this the correct way to write the command?  (Inlet zone ID = 6)

(if ( < 0 (pick-a-real "/rep/volume/volume-avg 6 , pressure n")) (set! mstop? #t))

Users guide does not explain how to write scheme programming.

Thanks for your help!