Constructing Sequences One Step at a Time

2016/09/18 by Towsner, Henry · 1 citation
#FOS: Mathematics #Logic (math.LO)

paper · doi:10.48550/arxiv.1609.05509

Abstract

We propose a new method for constructing Turing ideals satisfying principles of reverse mathematics below the Chain-Antichain Principle (CAC). Using this method, we are able to prove several new separations in the presence of Weak Konig's Lemma (WKL), including showing that CAC+WKL does not imply the thin set theorem for pairs, and that the principle "the product of well-quasi-orders is a well-quasi-order" is strictly between CAC and the Ascending/Descending Sequences principle, even in the presence of WKL.

Cited by

• Ordinal Analysis of Well-Ordering Principles, Well Quasi-Orders Closure Properties, and Σ_n-Collection Schema

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