Pythagoras, Pythagorean, Euclidean, Gravitational Lensing, Symmetry.
anything; instead is a “not obvious” intrinsic characteristic of the system. We wish to recognize the cause-effect action, starting in the basic symmetries I have shown, and ending in the c² = a² + b² equation, but it is just an illusion. Certainly, the backward way should be provable: a Vector