I suppose it’s not hard to grasp these properties:
2) categorical consistency
3) internal consistency (logical and non contradictory)
4) external consistency (external correspondence)
5) existential consistency (existential possibility)
6) moral consistency (moral objectivity)
And i suppose these tests are not terribly hard to grasp:
4) Full Accounting
But I suppose logic, mathematics, and grammar are not all that difficult either.
But then again, the ancients didn’t solve this problem.
It took 2500 years.