Problem $6$ The pull$-$up network of a complex gate is shown in Fig$\mathrm{.}4\mathrm{.}14.$ Determine the Boolean function implemented by the gate, and complete the electrical schematic by adding the pull$-$down network. Suppose that the gate is built with $W_N=125nm,W_P=250nm,$ and loaded by $C_L=4fF.$ How much propagation delay will it experience in response to $x_1$ making a low$-$to$-$high transition while other inputs rekain constant at $x_2=V_{DD},x_3=V_{DD},x_4=0$ and $x_5=0.$