I am most certainly not begging the question. I have addressed each of your points directly. I have a pretty good idea of Euclid's elements and the parallel pos

I am most certainly not begging the question. I have addressed each of your points directly. I have a pretty good idea of Euclid's elements and the parallel postulate. Constructivism in the philosophy of maths is the idea that it is necessary to find a specific example of something to prove it exists. That's an idea that significantly postdates Euclid.