Wadge-like degrees of Borel bqo-valued functions
نویسندگان
چکیده
We unite two well known generalisations of the Wadge theory. The first one considers more general reducing functions than continuous in classical case, and second extends reducibility from sets (i.e., { 0 , 1 stretchy="false">} \{0,1\} -valued functions) to alttext="upper Q"> Q encoding="application/x-tex">Q functions, for a better quasiorder . In this article, we consider reducibilities on generalise some results L. Motto Ros [J. Symbolic Logic 74 (2009), pp. 27–49] direction T. Kihara A. Montalbán [Trans. Amer. Math. Soc. 370 (2018), 9025–9044] direction: Our main result states that structure alttext="bold upper Delta Subscript alpha Superscript 0"> Δ α<!-- α </mml:msubsup> encoding="application/x-tex">\mathbf {\Delta }^0_\alpha -degrees plus gamma + γ<!-- γ }^0_{\alpha +\gamma }</mml:annotation> -measurable is isomorphic beta β<!-- β }^0_\beta</mml:annotation> }^0_{\beta these are generalized homomorphism order alttext="gamma"> encoding="application/x-tex">\gamma -th iterated -labeled forests.
منابع مشابه
On the Structure of the Wadge Degrees of Bqo-valued Borel Functions
In this article, we give a full description of the Wadge degrees of Borel functions from ω to a better quasi ordering Q. More precisely, for any countable ordinal ξ, we show that the Wadge degrees of ∆1+ξ-measurable functions ω ω → Q can be represented by countable joins of the ξ-th transfinite nests ofQ-labeled well-founded trees.
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ژورنال
عنوان ژورنال: Proceedings of the American Mathematical Society
سال: 2022
ISSN: ['2330-1511']
DOI: https://doi.org/10.1090/proc/15930