Does the endomorphism poset $P^P$ determine whether a finite poset $P$ is connected? An issue Duffus raised in 1978

Duffus wrote in his 1978 Ph.D. thesis, "It is not obvious that $P$ is connected and $P^P\cong Q^Q$ imply that $Q$ is connected", where $P$ and $Q$ are finite nonempty posets. We show that, indeed, under these hypotheses $Q$ is connected and $P\cong Q$.

Bibliographic Details
Main Author: Jonathan David Farley
Format: Article
Language:English
Published: Institute of Mathematics of the Czech Academy of Science 2023-12-01
Series:Mathematica Bohemica
Subjects:
Online Access:http://mb.math.cas.cz/full/148/4/mb148_4_1.pdf