the elimination method
this method, known as the elimination method, is used to obtain lower bounds.
the gate-elimination argument does the following. given a circuit for the function in question, we first argue that some variable 1 (or set of variables) must fan out to several gates. setting this variable to a constant will eliminate several gates. by repeatedly applying this process, we conclude that the original circuit must have had many gates.
[cite:;taken from @complexity_jukna_2012 chapter 1.6 a 3n lower bound for circuits]
the gate-elimination argument does the following. given a circuit for the function in question, we first argue that some variable 1 (or set of variables) must fan out to several gates. setting this variable to a constant will eliminate several gates. by repeatedly applying this process, we conclude that the original circuit must have had many gates.
[cite:;taken from @complexity_jukna_2012 chapter 1.6 a 3n lower bound for circuits]