Nice. You can also just copy the target number and paste it in, followed by your +4+4-4-4. I’m not convinced 73 is solvable with the official operators.
Those IP addresses were about the most believable thing in that episode. It’s occasionally amusing nonsense, requires about 1% concentration, and if you fall asleep in one episode and wake up in the next, you won’t need to reach for the remote.
The character was created specifically because when we write we use different length dashes to mean different things—subtraction through to a pause for thinking.
The automated test will have no difficulty telling them apart. Are you saying it’s hard looking at the results of this tests? You might need to use a font that makes that easy (I agree many monospaced fonts don’t, but that’s not the character’s fault. Or include a step that replaces en with 2 hyphens and em with 3.
Tbh, “I know nothing on the subject” ought to be enough. :)