For example, if the two inputs 10, 12 have identical voltages, the differential pair is split evenly and the circuitry creates a current sink that has {TAIL ~ the same current} as {HEAD ~ the current source} 
For example , if the two inputs 10 , 12 have identical voltages , the differential pair is split evenly and the circuitry creates a current sink that has { TAIL ~ the same current } as { HEAD ~ the current source }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD