My lecturer gave us the following problem today:
"A CMOS gate (with inputs A, B, C) consists of a pull-up network with 0 or more PMOS transistors, and a pull-down network with 0 or more NMOS transistors. The output is \$ f(A,B,C)\$. The truth table for \$ f(A,B,C) \$ has both 0's and 1's as outputs.
What is \$ f(1,1,1) \$?"
My initial thought was that \$ f(1,1,1) = 0 \$ since the PMOS transistors would be open (so that current can't run through) while the NMOS transistors would be closed and allowed a current through to GND resulting in a low output.
But since I don't know the actual boolean expression of \$ f(A,B,C) \$ can I really be sure this is the case?