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Natural Partial Orders

Published online by Cambridge University Press:  20 November 2018

R. A. Dean  and
Gordon Keller
R. A. Dean
Affiliation:
California Institute of Technology, Pasadena, California
Gordon Keller
Affiliation:
California Institute of Technology, Pasadena, California
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Let n be an ordinal. A partial ordering P of the ordinals T = T(n) = {w: w < n} is called natural if x P y implies x ⩽ y.

A natural partial ordering, hereafter abbreviated NPO, of T(n) is thus a coarsening of the natural total ordering of the ordinals. Every partial ordering of a finite set 5 is isomorphic to a natural partial ordering. This is a consequence of the theorem of Szpielrajn (5) which states that every partial ordering of a set may be refined to a total ordering. In this paper we consider only natural partial orderings. In the first section we obtain theorems about the lattice of all NPO's of T(n).

Type
Research Article
Information
Canadian Journal of Mathematics , Volume 20 , 1968 , pp. 535 - 554
Copyright
Copyright © Canadian Mathematical Society 1968

References

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