If
P is a partially ordered set and
R is a commutative ring,
then a certain differential graded
R-algebra

is defined from the
order relation on
P. The algebra

corresponding to
the empty poset is always contained in

so that

can be regarded as an

-algebra. The main result of
this paper shows that if
R is an integral domain and
P and
P' are
finite posets such that

as differential graded

-algebras, then
P and
P' are isomorphic.