[Doctor Stochastic]

Similarly, mathematical systems, as you note, cannot prove their own truth.

Not quite accurate. Plane geometry proves its own truth as does first order logic. Arithmetic and set theory do not.

[betty boop]

Plane geometry proves its own truth as does first order logic. Arithmetic and set theory do not.

I could be a brat and say "take it up with the person who made the observation." Instead, let me thank you, Doc, for putting this information into the record.

[js1138]

Plane geometry proves its own truth as does first order logic.

The may prove self-consistency, but they do not prove their "truth", that is their axioms.