field classes checked: 1138; failures: none
first Suzuki cases with r | q-1 (n, r): [(21, 7), (63, 7), (105, 7)]
ALL OK
nice -n 10 python3 -I zsig_arith.py  0.33s user 0.03s system 97% cpu 0.379 total
has_ppd(2,6)= False  has_ppd(3,2)= False  has_ppd(7,2)= False  has_ppd(2,1)= False  has_ppd(2,12)= True  has_ppd(5,2)= True
