Questions about orderings of filters and ultrafilters
I asked on MathOverflow several questions about ordering of filters and ultrafilters. Your participation in this research is welcome.
Intersecting elements of posets without least element
From the preprint of my article “Filters on Posets and Generalizations” (with little rewording): Definition 1. Let $latex \mathfrak{A}$ is a poset with least element $latex 0$. I will call elements $latex a$, $latex b$ in $latex \mathfrak{A}$ intersecting when exists c such that $latex c\ne 0$ and $latex c\subseteq a$ and $latex c\subseteq b$. […]
Isomorphism of filters expressed through reloids
In the new updated version of the article “Funcoids and Reloids” I proved the following theorem: Theorem Filter objects $latex \mathcal{A}$ and $latex \mathcal{B}$ are isomorphic iff exists a monovalued injective reloid $latex f$ such that $latex \mathrm{dom}f = \mathcal{A}$ and $latex \mathrm{im}f = \mathcal{B}$.
Counter-examples against two conjectures
I added counter-examples to the following two conjectures to my online article “Funcoids and Reloids”: Conjecture $latex (\mathsf{RLD})_{\mathrm{out}}(\mathcal{A}\times^{\mathsf{FCD}}\mathcal{B})=\mathcal{A}\times^{\mathsf{RLD}}\mathcal{B}$ for every filter objects $latex \mathcal{A}$ and $latex \mathcal{B}$. Conjecture $latex (\mathsf{RLD})_{\mathrm{out}}(\mathsf{FCD})f=f$ for every reloid $latex f$.
Filters on Posets and Generalizations updated
I uploaded updated version of Filters on Posets and Generalizations article and sent it to Armenian Journal of Mathematics for peer review. The main change in this version is a counter-example to the conjecture, that every weak partition of a filter object on a set is a strong partition. This example was suggested me by […]
Question: Complete classification of ultrafilters?
Are there a known complete classification of filters (or at least ultrafilters)? By complete classification I mean a characterization of every filter by a family of cardinal numbers such that two filters are isomorphic if and only if they have the same characterization. For definition of isomorphic filters see my article “Filters on Posets and […]
“Filters on Posets and Generalizations” updated
I updated my online draft of the “Filters on Posets and Generalizations” article, while a former version of it was submitted as a preprint into Armenian Journal of Mathematics. The main new feature of my online draft is the section “Complementive filter objects and factoring by a filter” added and also a counterexample against this […]
Every monovalued reloid is a restricted function
The conjecture “Every monovalued reloid is a restricted function” is proved true as a corollary of this theorem in the last revision of Funcoids and Reloids online article.
A monovalued reloid with atomic domain is atomic
In the last revision of Funcoids and Reloids online article I proved that every monovalued reloid with atomic domain is atomic. Consequently two following conjectures are proved true: Conjecture A monovalued reloid restricted to an atomic filter object is atomic or empty. Conjecture A (monovalued) function restricted to an atomic filter object is atomic or […]
A counter-example for a conjecture
In a new edition of Funcoids and Reloids article (section “Some counter-examples”) I wrote a counter-example against this conjecture, upholding that there exists a reloid with atomic domain, which is neither injective nor constant. The conjecture is equivalent to this my MathOverflow question, which was quickly solved by my colleagues. I just adapted the proof […]