Inside Carry Bypass Adder - 2
To sensitize red path we need: aiÅbi && ai+1Å bi+1
But: red path is false because when this condition is true MUX selects “1” input, i.e. directly from ci-1
Instead shorter lilac paths are sensitized and red path is not the critical path of the circuit
False paths first observed by V. Hrapcenko (Soviet Math. Dokl. 1978 )