Predicate Adjectives

   Okay, so doula is a predicate adjective.  I don't want to show my
ignorance but since I don't happen to keep Machen, Dana and Maney,
BDF or Roberston at work, perhaps someone can enlighten me as
to what sort of predicate adejctive this is.  My basic knowledge of
grammer says that in this case a predicate adjective would be
translated "members are slavish" just as ho anthropos kalos would be
translated "the man is good".  I don't recall learning anything in
three years of NT Greek that would have me put an "as" between
members and doula in translation, and in any case, the
translation "members as slaves" seems to make doula a substantive
adjective, not a predicate adjective.  Thanks.

Ken Litwak