English

Notes on the ordered set $A^A$. Part IV. The dual ${}^{A}\!A$ of $A^A$ for finite ordered sets

Rings and Algebras 2025-10-02 v2

Abstract

Let AA be a finite ordered set. Define the ordered set AAA^A as the set of all maps from AA to AA, ordered pointwise. Let AA{}^{A} A be the dual of AAA^A. We prove results in the spirit of Parts~I--III, but now using both AAA^A and AA{}^{A}A. For example, if (AAAAA)AAA \Bigl({}^{{}^{ {}^{ {}^{A}A}A}A}A\Bigr)^{A^{A^{A}}} is isomorphic to (BBBBB)BBB \Bigl({}^{ {}^{ {}^{ {}^{B}B}B}B}B\Bigr)^{B^{B^{B}}} for finite ordered sets AA and BB, then AA is isomorphic to BB.

Keywords

Cite

@article{arxiv.2509.20726,
  title  = {Notes on the ordered set $A^A$. Part IV. The dual ${}^{A}\!A$ of $A^A$ for finite ordered sets},
  author = {G. Grätzer},
  journal= {arXiv preprint arXiv:2509.20726},
  year   = {2025}
}

Comments

Based on Part I, incorrect