  In decision theory an act is a function from a set of conditions to the set
of real numbers. The set of conditions is a partition in some algebra of
events. The expected value of an act can be calculated when a probability
measure is given. We adopt an algebraic point of view by substituting the
algebra of events with a finite distributive lattice and the probability
measure with a lattice valuation. We introduce a partial order on acts that
generalizes the dominance relation and show that the set of acts is a lattice
with respect to this order. Finally we analyze some different kinds of
comparison between acts, without supposing a common set of conditions for the
acts to be compared.
