I trying to make a make a system takes in a 3 bit line and flips put to a specific bit, like two's complement. I am struggling to reconstruct my bit bus after manipulating my bits. Specifically, it says My bit lines are missing sources. I am struggling to understand how it thinks a line coming from the input pin and a line going into my mux is two destinations. I am tried multiple ways of connecting the wires and all seem to fail for me. Can someone please explain to me the best way to concatenate my buses for a function like this.
I'm not sure why you are using NAND gates like that instead of simple inverters, but the outputs of those NAND gates are single bit and you're trying to turn them into multi-bit busses. You can't just combine bits together with wire connections like that.