Final Answer:
The statement given "A relation schema R is in generalized 3NF if when a FD X --> A holds in R, then X is a superkey of R and A is a prime attribute of R" is false.
Step-by-step explanation:
Definition of Generalized 3NF:
In a relation schema R, if there's a functional dependency (FD) X → A, X need not be a superkey, and A need not be a prime attribute.
Generalized 3NF Requirements:
For Generalized 3NF, it's sufficient that X is a superkey or a part of a superkey, and A is a prime attribute or a part of a prime attribute.
Example:
If X is a proper subset of a superkey and A is a prime attribute, it satisfies Generalized 3NF.
Contradiction to Statement:
The statement incorrectly suggests that X must be a superkey and A must be a prime attribute for Generalized 3NF, which is not true.