The first voltage signal has {HEAD ~ a voltage swing} which is less than {TAIL ~ a voltage differential} between the voltage supply connections 
is less than
The first voltage signal has { HEAD ~ a voltage swing } which is less than { TAIL ~ a voltage differential } between the voltage supply connections
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH