If so, {HEAD ~ the power grid planner} modifies via or via array locations and reduces {TAIL ~ the number} of vias or via arrays of the power grid structure to determine refined dimensions and locations of power grid components 
reduces
If so , { HEAD ~ the power grid planner } modifies via or via array locations and reduces { TAIL ~ the number } of vias or via arrays of the power grid structure to determine refined dimensions and locations of power grid components
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH