Core Concepts
The equational theory of the Weihrauch lattice with multiplication is studied combinatorially, revealing its complexity and completeness.
Abstract
This content delves into the equational theory of the Weihrauch lattice with multiplication. It provides insights into its structure, connections to other classes, and challenges in understanding its complete axiomatization. The study focuses on distributive lattices, strong Weihrauch reducibility, and combinatorial descriptions. Various operations like ⊔, ⊓, ×, ∗ are analyzed along with their interactions and properties. The content also discusses related work in proof theory and explores the complexity of determining validity in this context.
Stats
Deciding which equations are true is complete for the third level of the polynomial hierarchy.
A key result is that 1 is definable in just (W, ≤W).
The equational theory of (Ws, ⊓, ×) and (W, ⊓, ×) coincide.
There is no complete axiomatization for inequality over (W, ⊓, ×).
The problem "is the inequality t ≤• u valid?" in the structure (W•, ⊓, ×) is Σp2-complete.
The problem "is the inequality t ≤• u valid?" in the structure (W•, ⊓, ×) is Σp2-complete.
The problem "is the inequality t ≤• u valid?" in the structure (W•, ⊓, ×) is Πp3-complete.
Quotes
"An easy induction over t shows that we can derive t ≤• t[1/x] × x."
"We start by investigating the equational theory of (W⋅⊓⋅×)."
"Our contributions focus on determining universal validity of equations."