(<=> (Partial-Order-Relation ?R)
(And (Reflexive-Relation ?R)
(Antisymmetric-Relation ?R)
(Transitive-Relation ?R)))
(=> (Total-Order-Relation ?R) (Partial-Order-Relation ?R))
(<=> (Total-Order-Relation ?R)
(And (Partial-Order-Relation ?R)
(=> (And (Instance-Of ?X (Exact-Domain ?R))
(Instance-Of ?Y (Exact-Domain ?R)))
(Or (Holds ?R ?X ?Y) (Holds ?R ?Y ?X)))))