A poset power
is the partially ordered set of isotone
maps from a partially ordered set
to a partially
ordered set
,
ordered pointwise. Thus
means
for every
(Farley and Grätzer 2026). The partial
order on the maps, rather than their composition, is the structure used in this
definition.
Farley and Grätzer (2026) proved that, for finite nonempty partially ordered sets and
,
an order isomorphism
implies an order isomorphism
. This resolves Duffus's reconstruction
question for poset powers (Farley and Grätzer 2026). It differs from poset
reconstruction from one-element-deletion decks. The nonempty hypothesis matters,
since the empty partially ordered set and
the one-element partially ordered set both
have a one-element self-power.