So i already got part of it but its the comparison part for the SOV that I am having a lot of trouble with. The lines are supposed to be either green or black and DEFINITELY not blue or red which is what im getting. Please help!

$6.$ Detecting signed overflow$$

First,$$you need to get the$$sign bits of the operands and output.$$Your goal is to build the image on the right. Here$$s how:

$$

$1.$ Splitters$$can take multi$-$bit wires and split them into single bits.

$*$ Make a$$Wiring $>$ Splitter$$and set its properties like so:$$

$*$

$*$ This will make something that looks like a little laser gun with a$3$on it$.$

$*$ The$$black side$$of the splitter accepts a $4-$bit number.

$*$ The$$green side$$will output$$bit $3($the MSB$)$ from that $4-$bit number.

$2.$ Now copy and paste that splitter a couple times for a total of three splitters.

$3.$ Make a$$new tunnel$$named$$MUX Out$$connected to$$the output of the MUX

$*$ that wire carries either$$B$$or$$~B$,$ depending on$$sub$.$

$4.$ To the$$input $($black$)$side of the splitters, connect the$$A$,$MUX Out, and$$O$$tunnels$.$

$*$ Make copies.$$Don$$t just make long wires from existing tunnels. That defeats the purpose of them!

$5.$ To the$$output $($green$)$side of the splitters,$$make and connect some new tunnels$$named$$SA$,$SB$,$ and$$SO$$for the sign of$$A$,$ the sign of$$MUX Out, and the sign of$$O$$respectively$.$

SA SB SO SOV

$0000$

$0011$

$0100$

$0110$

$1000$

$1010$

$1101$

$1110$

Now you have three tunnels,$$SA$,$SB$,$ and$$SO$$which carry$$just the signs$$of the two addends and the output. You can then copy and paste those tunnels to use them as inputs to the circuit you are about to build.

Using the method from the $$turning truth tables into Boolean functions$$ section above,$$turn this truth table on the right into a real circuit! The inputs are the tunnels you just made, and the output will be the$$SOV$$tunnel that is connected to the$$SOV$$LED$.$

Note:$$when you use that technique on this table, you may end up with situations where you have to$$AND three values together.$$You can either chain two $2-$input AND gates, or you can set the $$Number of Inputs$$ property on an AND gate to $3.$ The two possibilities are shown below.