is_freq verifies frequencies;
num contains basic numeric parameters;
init_num initializes basic numeric parameters;
freq contains current frequency information;
comp_freq computes current frequency information;
prob contains current probability information;
comp_prob computes current probability information.
Other frequencies:
cond_false,
cond_true,
cr,
dec_cor,
dec_err,
dec_neg,
dec_pos,
fa,
hi,
mi