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C873 — Derive the exact lattice-preservation criterion

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Study sequence: Calendar Key grids, domains and order (C872–C889) · Calendar Keys, phase & Sothic

C873 — Derive the exact lattice-preservation criterion

Question

When does a reduced Key p/q preserve hZ?

Inputs

{
  "keys": {
    "E": "25/23",
    "P": "70/69",
    "J": "300/299"
  }
}

Sources

[
  "C872 declared domains"
]

Opened utc

2026-09-28T02:46:40.097441+00:00

Results

{
  "theorem": {
    "path": "model/one_key_grid_theorem.json",
    "sha256": "99ef73648f71a47a6a4c02ada19ea51bdd1db7db3bd5264862b0864719ee7a34",
    "bytes": 232
  },
  "reduced_denominators": {
    "E": 23,
    "P": 69,
    "J": 299
  }
}

Finding

A Key preserves a declared grid exactly on hqZ. This is an input-domain condition, not a demand to round rational outputs or a license to apply a Key to every chronology.

Reassessment

Classify integer and Rounded domains for all three Keys and their intersection.

Checks

{
  "coprime": true,
  "grid_cancels": true
}

Closed utc

2026-09-28T02:46:40.097734+00:00

Record provenance

Exact record hash: 7874513c4f183894460c3b9ad772dfe9222ba95d4ef5223cbbcc59d2b79f937e

Source journal: Research_Cycles/C0832_C0931/journal.json

Linked sources and evidence

Edition and provenance

C873.md

SHA-256 4c7ea2e1dc1b648f9591eb4e63c4e1796d511379a0749f3c6c2cb1e6ba6863a5

C480–C1634/Research_Cycles/C0832_C0931/journal.json#C873