dependency function, horn function, BCNF normal form

From: Michelle Stone <>
Date: Wed, 30 Jan 2002 10:57:14 +0530
Message-ID: <a37vun$15t0g5$>

i was studying the theory of decomposing a relation into many smaller ones using BCNF normal form.

i was following the algorithm provided at

We have a dependency function AB(!C) + C(!A) [read (!A) as A-compliment]

It is said in the document that by adding the term ABC to the above dependency function you get the following HORN function

    C(!A) + D(!B) + AD(!C) + BC(!D)

HOW ???? First of all how does adding ABC to a dependency function yield a horn function?

Note: If the example given is not clear, pls refer to the .pdf file.

Thanks... Received on Wed Jan 30 2002 - 06:27:14 CET

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