A representation theorem is obtained for
contraction operators that are based on Levi's recent proposal
that selection functions should be applied to the set of saturatable
contractions, rather than to maximal subsets as in the AGM framework.
Furthermore, it is shown that Levi's proposal to base the selection on a
weakly monotonic measure of informational value guarantees the
satisfaction of both of Gärdenfors' supplementary postulates for
contraction. These results indicate that Levi has succeeded in constructing
a well-behaved operation of contraction that does not satisfy the postulate
of recovery.