I take it that some agreement has been arrived at as to how to define "solved" somewhere. Can anyone recall what it was?
If it means that every conceivable position legally arrived at has to be shown to be a win, loss or draw, it is not going to be done, even by a computer, any time soon.


but you cannot prove that 1+1=2, which
I think this statement is incorrect:
You are thinking of the Principia Mathematica, written by Alfred North Whitehead and Bertrand Russell. Here is a relevant excerpt: As you can see, it ends with "From this proposition it will follow, when arithmetical addition has been defined, that 1+1=2
Sure, defined, but not demonstrated. It’s a basic fact in math, everyone knows this, it’s common knowledge in math.