Solution

ID: past-exam-of-the-mathematics-course-of-the-university-of-cambridge/2018/iii/paper-121/1/iv/b/solution

For every tuple of parameters , an upward absolute formula transfers truth from the smaller structure to the larger one:
These definitions of directional set-theoretic absoluteness do not themselves require the structures to be transitive.

New to topics? Read the docs here!