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C608 — Derive covariance of anchored Keys

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Study sequence: Typed family interfaces and reviewed C631 explanation (C608–C631) · Family grammar & reading guides

C608 — Derive covariance of anchored Keys

Question

When does a translation commute with an anchored dilation?

Inputs

{
  "anchor": 14004,
  "point": 1446,
  "translation": 2,
  "Key": "300/299"
}

Sources

[
  "General anchored-Key grammar; C572"
]

Opened utc

2026-09-28T00:27:14.184026+00:00

Results

{
  "translate_output": 1406,
  "move_anchor_and_point": 1406,
  "move_point_only": "420396/299",
  "point_only_residual": "2/299",
  "identity": "T_t D(a,k)=D(a+t,k) T_t"
}

Finding

Translation commutes with dilation when the anchor moves with the frame. Holding the anchor while translating only the point leaves residual(k−1)t, here2/299. This formalizes why whole-pair and one-end changes behave differently.

Reassessment

Determine how allocation equivalence changes when interior junctions are retained.

Checks

{
  "covariance": true,
  "residual": true
}

Closed utc

2026-09-28T00:27:14.184353+00:00

Record provenance

Exact record hash: 94c0c4984af8effb5bd24e52a28db64fa404a490e7f33f7148c45ef3db5eee21

Source journal: Research_Cycles/C0532_C0631/journal.json

Edition and provenance

C608.md

SHA-256 8253cd69438ac4291e178acdedb8caa4deeb11475cc48011f420364a11345305

C480–C1634/Research_Cycles/C0532_C0631/journal.json#C608