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Isometry of space and its ballean implies equidistance?

Determine whether the metric d on an ultrametric space (X, d) must be equidistant whenever the ballean (\bar{B}_X, d_H) and the original space (X, d) are isometric.

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Background

Theorem 4.7 shows that when d is equidistant (all pairwise distances between distinct points are equal), the spaces (X, d) and (\bar{B}_X, d_H) are isometric, except for a finite nontrivial case. This question asks for the converse implication: does isometry of the space and its ballean force d to be equidistant?

An affirmative answer would classify all ultrametric spaces whose balleans are isometric to themselves, while a negative answer would require counterexamples and further structural analysis.

References

Question 6.3. Let (X, d) be an ultrametric space such that (\bar{B}_X, d_H) and (X, d) are isometric. Does it follows from this that d \colon X \times X \to \mathbb{R}{+} is equidistant?

Hausdorff distance between ultrametric balls (2509.00205 - Dovgoshey, 29 Aug 2025) in Question 6.3, Section 6