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Joseph Van Name

Publications and source records attributed to Joseph Van Name.

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Generalizations of Laver tables

We shall generalize the notion of a Laver table to algebras which may have many generators, several fundamental operations, fundamental operations of arity higher than 2, and to algebras where only some of the operations are self-distributive or where the operations satisfy a generalized version of self-distributivity. These algebras mimic the algebras of rank-into-rank embeddings $\mathcal{E}_λ/\equiv^γ$ in the sense that composition and the notion of a critical point make sense for these sorts of algebras.

math.LO

Ultraparacompactness and Ultranormality

In this note, we shall overview some results related to ultraparacompactness and ultranormality in the general topological and point-free contexts. This note contains some standard results and counterexamples along with some results which are not that well known and even of my new results.

math.GN

A Generalization of the notion of a $P$-space to proximity spaces

In this note, we shall generalize the notion of a $P$-space to proximity spaces and investigate the basic properties of these proximities. We therefore define a $P_{\aleph_{1}}$-proximity to be a proximity where if $A_{n}\prec B$ for all $n\in\mathbb{N}$, then $\bigcup_{n}A_{n}\prec B$. It turns out that the class of $P_{\aleph_{1}}$-proximities is equivalent to the class of $σ$-algebras. Furthermore, the $P_{\aleph_{1}}$-proximity coreflection of a proximity space is the $σ$-algebra of proximally Baire sets.

math.GN

Constructing Ultrapowers from Elementary Extensions of Full Clones

Let $A$ be an infinite set. Let $Ω(A)$ be the algebra over $A$ where every constant is a fundamental constant and every finitary function is a fundamental operation. We shall give a method of representing any algebra $\mathcal{L}$ in the variety generated by $Ω(A)$ as limit reduced powers and even direct limits of limit reduced powers of $\mathcal{L}$. If the algebra $\mathcal{L}$ is elementarily equivalent to $Ω(A)$, then this construction represents $Ω(A)$ as a limit ultrapower and also as direct limits of limit ultrapowers of $Ω(A)$. This method therefore gives a method of representing Boolean ultrapowers and other generalizations of the ultrapower construction as limit ultrapowers and direct limits of limit ultrapowers.

math.LO

A Duality Between Non-Archimedean Uniform Spaces and Subdirect Powers of Full Clones

A uniform space is said to be non-Archimedean if it is generated by equivalence relations. If $λ$ is a cardinal, then a non-Archimedean uniform space $(X,\mathcal{U})$ is $λ$-totally bounded if each equivalence relation in $\mathcal{U}$ partitions $X$ into less than $λ$ blocks. If $A$ is an infinite set, then let $Ω(A)$ be the algebra with universe $A$ and where each $a\in A$ is a fundamental constant and every finitary function is a fundamental operation. We shall give a duality between complete non-Archimedean $|A|^{+}$-totally bounded uniform spaces and subdirect powers of $Ω(A)$. We shall apply this duality to characterize the algebras dual to supercomplete non-Archimedean uniform spaces.

math.GN

Duality Between Uniform Spaces and Boolean Algebras

In this note we shall generalize the Stone duality between compact totally disconnected spaces and Boolean algebras to a duality between all complete non-Archimedean uniform spaces and Boolean algebras.

math.GN