NON-OBVIOUS...INVENTIVENESS
COULD-WOULD (Non-obvious)
Considering whether or not the claimed invention, starting from the closest prior art and the objective technical problem, would have been obvious to the skilled person.
Is there any teaching in the prior art, as a whole, that would, not simply could, have prompted the skilled person, faced with the objective technical problem, to modify or adapt said closest prior art while taking account the teaching of the whole and arrive at something falling within the terms of the claims, and thus achieving what the invention achieves.