Searching problems above arithmetical transfinite recursion

التفاصيل البيبلوغرافية
العنوان: Searching problems above arithmetical transfinite recursion
المؤلفون: Suzuki, Yudai, Yokoyama, Keita
سنة النشر: 2023
المجموعة: Mathematics
مصطلحات موضوعية: Mathematics - Logic
الوصف: We investigate some Weihrauch problems between $\mathsf{ATR}_2$ and $\mathsf{C}_{\omega^\omega}$ . We show that the fixed point theorem for monotone operators on the Cantor space (a weaker version of the Knaster-Tarski theorem) is not Weihrauch reducible to $\mathsf{ATR}_2$. Furthermore, we introduce the $\omega$-model reflection $\mathsf{ATR}_2^{\mathrm{rfn}}$ of $\mathsf{ATR} $ and show that it is an upper bound for problems provable from the axiomatic system $\mathrm{ATR}_0$ which are of the form $\forall X(\theta(X) \to \exists Y \eta(X, Y ))$ with arithmetical formulas $\theta, \eta$. We also show that Weihrauch degrees of relativized least fixed point theorem for monotone operators on the Cantor space forms a linear hierarchy between $\mathsf{ATR}^{\mathrm{rfn}}$ and $\mathsf{C}_{\omega^\omega} $.
نوع الوثيقة: Working Paper
URL الوصول: http://arxiv.org/abs/2305.07321
رقم الانضمام: edsarx.2305.07321
قاعدة البيانات: arXiv