Dependency-Preserving decomposition (Theory)

[Terabyte]

Hey,
Just running through some practice papers for a database exam and I'm stuck on dependancy preserving decomposition

Relation T defined over attributes A,B,C,D,E
Functional Dependancies: 
B->E
E->A
A->D
D->E

Determine if decomposition of T into AB, BCD, ADE will be dependency preserving

Could anyone show me how to work this out?

Thanks for any help.

[drpaudyal]

To check wheather this decompostion will preseve the dependency simply calcuate the closurse union of these three decomposed relations, see if it logically implies the original FDs.

What I mean by that is
R1(A,B), R2(BCD) and,R3( ADE)

(R1 UNION R2 UNION R3 UNION) + = F+

(ABCDE)+ =F+

ABCDE supports all the originally dependency. So this decomposition preseves the dependency