Past exam of the year 1 of the computer science course of the University of Oxford / 2022 / Digital systems, linear algebra, introduction to formal proof resit / 3 / b

The pull-down Boolean function is $ab\vee bc=b(a\vee c)$. A conducting pull-down makes $z=0$, soIn particular, if $b=0$ the output is always high; if $b=1$, the output is high precisely when both other inputs are low. These cases give the truth table without confusing a network's conducting condition with the output voltage.