NormalizAtion concept in DB

Is this statment correct?

"A Prime attribute can be transitively dependon a key in a BCNF relation" ?

according to me it is wrong

if it is wrong then what is the Normal Form of given Relation

R(A,B,C,D) and its functional dependenc开发者_JS百科y set is { AB->C ,AB->D , CD->A ,CD->B ,AB->CD }

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A BCNF relation can satisfy a transitive FD like A->B->C only if A and B are both superkeys or if either A->B or B->C is trivial.

Gramatical errors aside the statement is strictly correct - it's just not very interesting or useful. Normally we are interested in whether a relation satisfies any non-superkey, non-trivial FDs, which are the ones that BCNF prohibits. I suggest you recheck the quotation to make sure you have it right.