11. *An example comes from reversing the direction of inequalities in a partial order . 12. Below are four different Hasse diagrams for this partial order . 13. Not every partial order obeys the transitive law for incomparability. 14. When a partial order is negative, the overall order is usually considered as undefined. 15. The specialization order yields a tool to obtain a partial order from every topology. 16. The permutations for which this partial order is series-parallel are exactly the separable permutations. 17. A group " G " with a partial order is called an ordered group. 18. The defining axioms of effect algebras guarantee that d " is a partial order . 19. In the following, partial orders will usually just be denoted by their carrier sets. 20. It follows that the relation defined in this way is only a partial order .
