The isometry degree of a computable copy of ℓp
Timothy H. McNicholl, D. M. Stull · Computability · 2019
When p is a computable real so that [Formula: see text], we define the isometry degree of a computable presentation of [Formula: see text] to be the least powerful Turing degree d by which it is d-computably isometrically isomorphic to the standard presentation of [Formula: see text]. We show that this degree always exists and that when [Formula: see text] these degrees are precisely the c.e. degrees.