[Gimp-user] ht outline transparent areas in one file and select the same in another?

[ottenm <forums gimpusers com>]

Sorry for the confused sounding subject!

> From a png of a whole dollar bill (A) I made a png of a dollar bill torn in half
(B) where the other half is gone/transparent.  Now, I'd like to make a third
file based on these two of the exact *other* half of the dollar bill.  i.e.,
keep everything in A that is transparent in B, and delete everything in A that
is not transparent in B.

I'm thinking, "Select the transparent area of B (how?), select that same shape
in A (how?), invert the selection, and hit delete."

Thanks for any help/suggestions-

-- 
ottenm (via www.gimpusers.com/forums)