When we get down to the basic problem, we have an appearance. Then we give it a label. Identification follows appearance. Then conventional discourse can ensue. Underneath the all identifications is the idea of "is".
Well, you are saying that underneath the all identifications is the idea of "is", but still, you begin with appearance.
I am thinking here that "is" or "is not" are conceptual, and only follow the initial arising of an appearance, the raw arising of appearance to the senses.
What we experience as appearances is so unfathomably vast, and occurring so rapidly, i mean, you just need to glance around the room and already you are processing millions of bits of information about shape depth, color and so forth, and we are perceiving things we are not even aware that we are perceiving until they are brought to out attention, like when one's foot falls asleep.
I am not disagreeing with you at all about the illusory quality of "is' or 'is not", I am just wondering about the order of things.
By the way, getting back to an earlier discussion in this thread, i meantioned sunlight and you pointed out that sunlight has a cause, and so it is conditional and not eternal and so on. So, let me take it in the other direction.
What about total darkness? Total darkness is a complete lack of light.
If a person has their eyes completely covered, one will not know if one is in the dark room or not.
Thus, when one is in a totally dark space (accidentally buried alive) with one's eyes open,
There is the experience of something which does not arise conditionally, and this experience occurs through perception.
In other words, because my eyes are open I can see that the space is totally dark
Now, I suppose it could be argued that darkness is dependent on no light
and thus results from causes, or only exists in some relative context.
However, I do not think this is a logical argument, because the introduction of light can only be considered as an interruption.
Unlike the comparing, say, hot and cold, where each has something causing it, there is nothing actually causing darkness, yet that darkness can be directly witnessed because there is still the functioning of awareness.
So, perhaps sunyata can be directly experienced, precisely as
both the non-arising of an experiencer and the non arising of an object of experience.