Aah, sorry for the confusion!
The lights are a combination of two LVARs:
LVL CHG: (A:AUTOPILOT FLIGHT LEVEL CHANGE, Bool) 1 == (L:XMLVAR_AirSpeedIsInMach, Bool) 0 == and
MACH: (A:AUTOPILOT FLIGHT LEVEL CHANGE, Bool) 1 == (L:XMLVAR_AirSpeedIsInMach, Bool) 1 == and