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2025-07-29 WR

Rearrange the digits in ⟨125034⟩ to meet the rules below.

⟨5th 4th 3rd 2nd 1st 0th⟩

✅Match
5th|2nd → 0
Jump(2,4) = 2

⛔Avoid
⟨ ▧ ▧ ▧ ▢ ▢ ▢ ⟩, Σ▧ ≤ Σ▢
⟨⋯ a ⋯ 1 ⋯⟩, a = 2|4|5
⟨ ⁵ᵗʰa         ⁰ᵗʰb ⟩, (ab)₁₀ ≤ 30

#125034_v2.9


       ┌───┬───┬───┬───┬───┬───┐
       │5th│4th│3rd│2nd│1st│0th│▒
       ╞═══╪═══╪═══╪═══╪═══╪═══╡▒
Step 1 │   │ 1 │   │   │   │   │▒
       ├───┼───┼───┼───┼───┼───┤▒
Step 2 │   │ 1 │   │ 0 │   │   │▒
       ├───┼───┼───┼───┼───┼───┤▒
Step 3 │ 3 │ 1 │   │ 0 │   │   │▒
       ├───┼───┼───┼───┼───┼───┤▒
Step 4 │ 3 │ 1 │   │ 0 │ 5 │   │▒
       ├───┼───┼───┼───┼───┼───┤▒
Step 5 │ 3 │ 1 │ 4 │ 0 │ 5 │   │▒
       ├───┼───┼───┼───┼───┼───┤▒
Step 6 │ 3 │ 1 │ 4 │ 0 │ 5 │ 2 │▒
       └───┴───┴───┴───┴───┴───┘▒
        ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒

Proof of 2025-07-29 WR
══════════════════════

Notation: if nth -> a, then we write [nth] = a.

To avoid ⛔「⟨⋯ a ⋯ 1 ⋯⟩, a = 2|4|5」, we need

(1) 1 is to the left of 2,4,5.

This implies

(2) 1 = [5th] | [4th] | [3rd].

If 1 = [5th], then we cannot avoid ⛔「⟨ ⁵ᵗʰa         ⁰ᵗʰb ⟩, (ab)₁₀ ≤ 30」. Else if 1 = [3rd]:

┌───┬───┬───┬───┬───┬───┐
│5th│4th│ 3▲│2nd│1st│0th│
╞═══╪═══╪═══╪═══╪═══╪═══╡
│   │   │ 1 │   │   │   │
└───┴───┴───┴───┴───┴───┘

then we cannot match (1) and ✅「Jump(2,4) = 2」 at the same time. Therefore, 1 = [4th]:

       ┌───┬───┬───┬───┬───┬───┐
       │5th│ 4■│3rd│2nd│1st│0th│▒
       ╞═══╪═══╪═══╪═══╪═══╪═══╡▒
Step 1 │   │ 1 │   │   │   │   │▒
       └───┴───┴───┴───┴───┴───┘▒
        ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒

--- Idle ---
┌───┬───┬───┬───┬───┬───┐
│   │ 2 │ 5 │ 0 │ 3 │ 4 │
└───┴───┴───┴───┴───┴───┘

Then we consider how to match ✅「5th|2nd → 0」. If [5th] = 0:

┌───┬───┬───┬───┬───┬───┐
│ 5▲│4th│3rd│2nd│1st│0th│
╞═══╪═══╪═══╪═══╪═══╪═══╡
│ 0 │ 1 │   │   │   │   │
└───┴───┴───┴───┴───┴───┘

--- Idle ---
┌───┬───┬───┬───┬───┬───┐
│   │ 2 │ 5 │   │ 3 │ 4 │
└───┴───┴───┴───┴───┴───┘

then we would fail to avoid ⛔「⟨ ▧ ▧ ▧ ▢ ▢ ▢ ⟩, Σ▧ ≤ Σ▢」. So, we have 0 = [2nd] instead:

       ┌───┬───┬───┬───┬───┬───┐
       │5th│4th│3rd│ 2■│1st│0th│▒
       ╞═══╪═══╪═══╪═══╪═══╪═══╡▒
       │   │ 1 │   │   │   │   │▒
       ├───┼───┼───┼───┼───┼───┤▒
Step 2 │   │ 1 │   │ 0 │   │   │▒
       └───┴───┴───┴───┴───┴───┘▒
        ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒

--- Idle ---
┌───┬───┬───┬───┬───┬───┐
│   │ 2 │ 5 │   │ 3 │ 4 │
└───┴───┴───┴───┴───┴───┘

By (1), the boxes to the right of 1 are occupied by 2,4,5. It follows that 3 = [5th]:

       ┌───┬───┬───┬───┬───┬───┐
       │ 5■│4th│3rd│2nd│1st│0th│▒
       ╞═══╪═══╪═══╪═══╪═══╪═══╡▒
       │   │ 1 │   │ 0 │   │   │▒
       ├───┼───┼───┼───┼───┼───┤▒
Step 3 │ 3 │ 1 │   │ 0 │   │   │▒
       └───┴───┴───┴───┴───┴───┘▒
        ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒

--- Idle ---
┌───┬───┬───┬───┬───┬───┐
│   │ 2 │ 5 │   │   │ 4 │
└───┴───┴───┴───┴───┴───┘

By ✅「Jump(2,4) = 2」, 2 and 4 are separated by 2 boxes. There is only one way to do so:

┌───┬───┬───┬───┬───┬───┐
│5th│4th│ 3▲│2nd│1st│ 0▲│
╞═══╪═══╪═══╪═══╪═══╪═══╡
│ 3 │ 1 │ ▬ │ 0 │   │ ▬ │
└───┴───┴───┴───┴───┴───┘

whence 5 = [1st]:

       ┌───┬───┬───┬───┬───┬───┐
       │5th│4th│3rd│2nd│ 1■│0th│▒
       ╞═══╪═══╪═══╪═══╪═══╪═══╡▒
       │ 3 │ 1 │   │ 0 │   │   │▒
       ├───┼───┼───┼───┼───┼───┤▒
Step 4 │ 3 │ 1 │   │ 0 │ 5 │   │▒
       └───┴───┴───┴───┴───┴───┘▒
        ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒

--- Idle ---
┌───┬───┬───┬───┬───┬───┐
│   │ 2 │   │   │   │ 4 │
└───┴───┴───┴───┴───┴───┘

Finally, to avoid ⛔「⟨ ▧ ▧ ▧ ▢ ▢ ▢ ⟩, Σ▧ ≤ Σ▢」, we finish by

       ┌───┬───┬───┬───┬───┬───┐
       │5th│4th│ 3■│2nd│1st│ 0■│▒
       ╞═══╪═══╪═══╪═══╪═══╪═══╡▒
       │ 3 │ 1 │   │ 0 │ 5 │   │▒
       ├───┼───┼───┼───┼───┼───┤▒
Step 5 │ 3 │ 1 │ 4 │ 0 │ 5 │   │▒
       ├───┼───┼───┼───┼───┼───┤▒
Step 6 │ 3 │ 1 │ 4 │ 0 │ 5 │ 2 │▒
       └───┴───┴───┴───┴───┴───┘▒
        ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒

--- Idle ---
┌───┬───┬───┬───┬───┬───┐
│   │   │   │   │   │   │
└───┴───┴───┴───┴───┴───┘

Q.E.D.

#125034_v2.9