Tarski [Tarski] showed that for any set X, its set w(X) of
well-orderable subsets has cardinality strictly greater than that of
X, even in the absence of the axiom of choice. We construct a
Fraenkel-Mostowski model in which there is an infinite strictly
descending sequence under the relation |w(X)| = |Y|. This contrasts
with the corresponding situation for power sets, where use of Hartogs’
ℵ-function easily establishes that there can be no infinite
descending sequence under the relation |𝒫(X)| = |Y|.