I'm reading and re-reading your last sentence but can't make heads nor tails of it, can you please expand on what you mean there?

As to the 1+1 thing - reads like pure sophistry to me. It doesn't matter if the chairs are part of the room or not, it doesn't even matter if there are any chairs at all, the fact remains that if you take an item, a purely abstract item, a totally shapeless and formless item that has the completely arbitrary assigned value of one and add to it another item that has the same arbitrary value you get the sum of those values when you group them together. Yes, this is predicated on an axiom but the axiom is for us, in our general reality in this universe undeniably true. Until it maybe isn't in some hypothetical future but until such a time we have no reason to assume so and thus such a hypothetical overturning of the axiom is completely irrelevant, a navel gazing exercise. The example of adding items is a very apt one because it demonstrably applies to non-human species as well. Many kinds of birds can count, apes can too, as well as elephants and highly probably many many other animals throughout the animal kingdom. This operation transcends not only any ideological stance both geographically and historically but even entire species. What more reasonable proof of universality do you want that knowledge is not tethered to its historical origins?