Under certain definitions of "1" "2" and "+", 1 + 1 = 2. But it's completely possible to define mathematics where 1+2 doesn't equal 2. It just so happens that we have a universally-shared convention on arithmetic.
But that simplicity quickly breaks down when people don't share the underlying axioms, and "fact checking" regularly operates in that space. For example, does 1+1 = the number of human genders? Everyone where I'm from would say that's an obviously true fact, but a lot of the folks who run Twitter would disagree.
But that simplicity quickly breaks down when people don't share the underlying axioms, and "fact checking" regularly operates in that space. For example, does 1+1 = the number of human genders? Everyone where I'm from would say that's an obviously true fact, but a lot of the folks who run Twitter would disagree.