code: def tern_incr_digits(prec, maxexp, itr):
      if itr is None:
          lst1 = range(prec + 30)
          lst2 = range(prec + 30)
          lst3 = range(prec + 30)
      else:
          lst1 = sample(range(prec + 30), itr)
          lst2 = sample(range(prec + 30), itr)
          lst3 = sample(range(prec + 30), itr)
      for m in lst1:
          for n in lst2:
              for p in lst3:
                  x = from_triple(randsign(), ndigits(m), 0)
                  y = from_triple(randsign(), ndigits(n), 0)
                  z = from_triple(randsign(), ndigits(p), 0)
                  yield x, y, z
  
imports: from random import randrange, sample
  from fractions import Fraction
  from randfloat import un_randfloat, bin_randfloat, tern_randfloat
label_desc: Use image node_id 38 for calling a global function with example usage: tern_incr_digits(prec, maxexp, itr) without return types