How to see if the employee is already enrolled to a life event in Benefit fast formula

Summarry

I have to do some calculation for an employee only when they are not enrolled to the benefit life event. Is there a benefit fast formula function I can use for this ?

Example :

l_mon = 12 - FLOOR(months_between(l_last_date,l_first_date))

l_defined_rate = to_num(GET_TABLE_VALUE('BEN_HSSA_VAL_V2', 'COVERAGE', l_BenEnt, '0'))

l_cvg = (l_defined_rate/12) * l_mon

This calculation should take place only if the employee is not enrolled to the plan. For this I am using the function :

l_if_pl_enrolled = ben_fn_get_char_value('BEN_PRTT_ENRT_RSLT'