  We define a Grothendieck ring of pairs of complex quasi-projective varieties
(that is a variety and a subvariety). We describe $\lambda$-structures and a
power structure on/over this ring. We show that the conjectual symmetric power
of the projective line with several orbifold points described by A.Fonarev is
consistent with the symmetric power of this line with points as a pair of
varieties.
