Dependencies using user defined data types

Hi all,

I have created a dependency for one of the characteristics of a user-defined data type- I am working with the structure shown below:

CLASS X Type 022

A

A_1

A_2

A_3

B

C

D

D_1

D_2

D_3

A_1, A_2 and A_3 correspond to the user defined data type of A. I have created a procedure in A_1 which says:

$SELF.D_1 = $SELF.D_1 + $SELF.A_1 .

The procedure seems to be OK but the system does not calculate anything. If I use $SELF.D_1 = $SELF.B + $SELF.C . then the procedure works fine.

Is it possible to use subcharaceristics in a procedure?

Thanks a lot in advance, good points will be rewarded.