People say shit like this, but it's just not true. If darkness is the absence of light, then it's dark so long as there isn't light. If you observe a universe where there are no photons, it'd be dark everywhere. (it'd also not have the EM force, but let's put that aside for now.) You can have darkness without light, but if you aren't aware of light, then you simply wouldn't have a word for darkness; you are confusing the conceptualization of thing with the thing itself. In my circles, we refer to this fallacy as confusing the map and the territory.
I'm a mathematician. I work in multidimensional spaces. Did you know you can have coordinate systems with boundaries? You can also have universes where movement is possible in a particular direction, but not the other. We actually live in such a universe; you can only move forward in time.
Your entire argument is "I can't imagine darkness without light, therefore it's logically impossible." All you've proven is that you lack an imagination and don't understand logic.
You're still limiting your thinking too much. Would you say it's possible for something to be impossible, or that that's simply not possible because everything is possible?
But that assumption, of how reality works, is based on the premise that reality is, has always been, and can only work that way. Maybe opposites coexist in some other concept of reality?
What you are probably imagining when talking about 0 and 1 are their representatives in the "integer ring" or maybe the ring of real numbers. Both are simply definitions made by humans and in no way universal truths.
How many years have you studied mathematics? If you really believe that, it can't be more than 2 after high-school.
Edit: better question: Can you define "equivalence relation"? I don't want you to be creative, I want the standard definition you come across in any foundations class.
This is actually wrong. You can have an equivalence relation where 0 is equivalent to 1. Furthermore, in the Trivial Ring (that is, the ring algebra of a single element) the multiplicative identity (written as 1) and the and the additive identity (written as 0) are the same element, and thus in the context of the trivial ring 0=1. Isn't that fascinating?