at least one snubber capacitor connected in series with the thyristor circuit diode in {HEAD ~ parallel} with {TAIL ~ the respective gate turn off thyristor}, and 
with
at least one snubber capacitor connected in series with the thyristor circuit diode in { HEAD ~ parallel } with { TAIL ~ the respective gate turn off thyristor } , and
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH