The 4-colour theorem is not outside mathematics. I think I sort of understand what you mean by ‘demonstrated satisfactorily’ but in my experience such demonstrations aren’t worth much, not only can they be wrong in principle, they are often wrong in practice. Mathematics is nothing if not counter-intuitive.
The 4-colour theorem is not outside mathematics. I think I sort of understand what you mean by ‘demonstrated satisfactorily’ but in my experience such demonstrations aren’t worth much, not only can they be wrong in principle, they are often wrong in practice. Mathematics is nothing if not counter-intuitive.