What ar the allowed functions in expression questions in survey

The list I’m working from is here:

However, random() was added as of yesterday. However, I can’t see round, ceil or floor so this is what I’ve come up with to allocate to three groups

Expression 1 assigns a random value for participant from 1.0000 to 4.0000

random()*3+1

Expression 2 assigns a nominal value for group

iif({participant} > 3, 'both', iif({participant} > 2, 'auditory', 'visual') )