Pretty much all of them?

Take the Euclidian proof (#7). The order of the reasoning is important, because each step builds upon what was proved in the previous step.

You can think of proofs as chains of logic. Assuming A, B, and C.

  (A+B) -> X, (A+C)-> Y
  (X+Y) -> Z

Now you need to prove both X and Y before Z. But, you could prove Y before X so It's not a strict question of order but one of dependence.

Going back to the proof 7 the line For the same reason also means the order is not strict and you could swap those lines without changing the logic.