This is known as Hempel's requirement of high probability. Empirical theories can't be proved true or false as mathematical theories can. Evidence can be found to for or against a theory. Confirmation as distinct from truth. Any evidence E for a theory T is also evidence for a logically equivalent theory T'.
All ravens are black .
Assumptions Generalisations are confirmed by their instances. Any evidence E for a theory T is also evidence for a logically equivalent theory T'. A consequence of GTR is that light rays are deflected in the presence of matter. Any evidence E for a theory T is also evidence for a logically equivalent theory T'. The Paradoxes Resolved Ravens paradox.