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JOURNALS // Izvestiya Vysshikh Uchebnykh Zavedenii. Matematika // Archive

Izv. Vyssh. Uchebn. Zaved. Mat., 2025 Number 10, Pages 88–93 (Mi ivm10131)

Brief communications

A low scattered linear order of rank $2$ with no computable copy

M. V. Zubkov

Kazan Federal University, 18 Kremlyovskaya str., Kazan, 420008 Russia

Abstract: In R. Downey's 1998 survey, the question was posed: describe order properties $P$ such that for any low linear order $L$, if $P(L)$ holds, then $L$ has a computable copy. This paper shows that the property of being scattered is not such a property. Namely, a low scattered linear order of rank $2$ with no computable copy is constructed.

Keywords: low linear order, scattered linear order, computable linear order.

UDC: 510.53, 512.562

Received: 29.08.2025
Revised: 29.08.2025
Accepted: 26.09.2025

DOI: 10.26907/0021-3446-2025-10-88-93



© Steklov Math. Inst. of RAS, 2026