3 papers
math.LO2021
A Feiner Look at the Intermediate Degrees
Denis R. Hirschfeldt, Asher M. Kach, Antonio Montalbán
We say that a set is if membership of in is a question, uniformly in . A set is low for -Feiner if every set that is $Δ^0_{(n)…
math.LO2018
The determined property of Baire in reverse math
Eric P. Astor, Damir Dzhafarov, Antonio Montalbán +2
We define the notion of a determined Borel code in reverse math, and consider the principle , which states that every determined Borel set has the property of Baire. We show t…
math.LO2017
On the structure of the Wadge degrees of BQO-valued Borel functions
Takayuki Kihara, Antonio Montalbán
In this article, we give a full description of the Wadge degrees of Borel functions from to a better quasi ordering . More precisely, for any countable ordinal $…