Depending on what programming language you are using, and precisely how you've coded a function, which exact numerical data types, and functions/methods you are using...

Actually attempting to divide something by zero will result in either NaN, Not a Number, Null, or an Unhandled Exception, as an... output value/error type.

I tried to explain 'void' a bit better, Im not personally familiar with any code language that'll have 'void' as an output/error type when you try to divide by zero... but most people use the phrase 'null and void', so, my brain associated that word in as well.

As far as how those terms refer back to an anarchist mindset?

I am 'not a number', I am a human being, so are all others.

Null or nulled out has been a cyberpunkish slang term to refer to both an individual being seen as inherently unspecial, not unique, made into just another consumer/commodity... as well referring to actually killing or otherwise neutralizing someone or something... for decades now.

It seems you get the less programmy meaning of 'unhandled exception', in the 'become ungovernable' sense, but now hopefully you also get the math/programmer meaning, and see how these all work as double entendres or at least have somewhat esoteric meanings.

... The problem is that they don't work as well in common speech as a replacement for common nouns... with at least one of the reasons why that is the case being that evidently the multifarious meanings are too esoteric, lol, which is why I said I was mostly proposing these as jokes.