We got a realist over here!!! I repeat: a realist in the house!

Real scientists don’t call others armchair scientists, it’s just belittling. Do you resort to ad hominem because you feel like your argument is not strong enough, so you have to try to attack the person as well?

How is an “actual system” distinct from a formal system? What is actual?

I assume it's related to the aphorism:

In theory, theory and practice are the same. In practice, they are not.

Yes, but in this case, it's all mathematics and computation. The messy analogue real world isn't involved in either.