_RL hl_period
& hl_period, hl_StartTime,
I hl_StartTime, hl_period, hl_RepCycle,
I 'exf', 'hl_', hl_period,
I hl_period, exf_inscal_hl, hl_const,
& hl_RepCycle, hl_period, hl_StartTime,
hl_period = 0.0 _d 0
I hl_file, hl_RepCycle, hl_period,