On the Nielsen-Schreier Theorem in Homotopy Type Theory
نویسندگان
چکیده
We give a formulation of the Nielsen-Schreier theorem (subgroups free groups are free) in homotopy type theory using presentation as pointed connected 1-truncated types. show special case finite index subgroups holds constructively and full follows from axiom choice. an example boolean infinity topos where our does not hold stronger "untruncated" version is provably false theory.
منابع مشابه
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ژورنال
عنوان ژورنال: Logical Methods in Computer Science
سال: 2022
ISSN: ['1860-5974']
DOI: https://doi.org/10.46298/lmcs-18(1:18)2022