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2026-04-28 WR

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

⟨ ⁵ᵗʰ▨ ⁴ᵗʰ▨ ³ʳᵈ▨ ²ⁿᵈ▨ ¹ˢᵗ▨ ⁰ᵗʰ▨ ⟩

✅Match
min ⊢5⊣ = 2

⛔Avoid
⟨⋯ ᵃb ⋯⟩, a+b=2
⟨⋯ 3 ⋯ 2 ⋯ 5 ⋯⟩
⟨ ⁵ᵗʰa     ²ⁿᵈb ¹ˢᵗc   ⟩, (abc)₁₀ ≤ 132
⟨ ⁵ᵗʰa ⁴ᵗʰb         ⟩, (ab)₁₀ ≥ 30
⟨⋯ ᵃb ⋯⟩, |a-b|=3

#125034_v2.13


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

Proof of 2026-04-28 WR
══════════════════════

To avoid ⛔「⟨ ⁵ᵗʰa ⁴ᵗʰb         ⟩, (ab)₁₀ ≥ 30」, we need [5th] ≤ 2. Combining this with ⛔「⟨ ⁵ᵗʰa     ²ⁿᵈb ¹ˢᵗc   ⟩, (abc)₁₀ ≤ 132」, we have

(1) [5th] = 1 or 2.

If it is 2, then we fail to avoid ⛔「⟨⋯ ᵃb ⋯⟩, |a-b|=3」. Therefore

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

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

Next, we consider where to place 5.

To match ✅「min ⊢5⊣ = 2」, 5 cannot be adjacent to 1:

      ┌───┬───┬───┬───┬───┬───┐
      │5th│4th│3rd│2nd│1st│0th│
      ╞═══╪═══╪═══╪═══╪═══╪═══╡
(2.1) │ 1 │ / │   │   │   │   │
      └───┴───┴───┴───┴───┴───┘

To avoid ⛔「⟨⋯ ᵃb ⋯⟩, |a-b|=3」, we cannot have 5 = [2nd] as well.

      ┌───┬───┬───┬───┬───┬───┐
      │5th│4th│3rd│2nd│1st│0th│
      ╞═══╪═══╪═══╪═══╪═══╪═══╡
(2.2) │ 1 │ / │   │ / │   │   │
      └───┴───┴───┴───┴───┴───┘

If 5 = [0th], then using ✅「min ⊢5⊣ = 2」, we have

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

and we will match ⛔「⟨⋯ 3 ⋯ 2 ⋯ 5 ⋯⟩」, which is a contradiction. Therefore, 5 != [0th].

      ┌───┬───┬───┬───┬───┬───┐
      │5th│4th│3rd│2nd│1st│0th│
      ╞═══╪═══╪═══╪═══╪═══╪═══╡
(2.3) │ 1 │ / │   │ / │   │ / │
      └───┴───┴───┴───┴───┴───┘

If 5 = [1st]:

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

then to match ✅「min ⊢5⊣ = 2」 and avoid ⛔「⟨⋯ ᵃb ⋯⟩, a+b=2」 at the same time, we need 2 = [2nd]:

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

Then, to avoid ⛔「⟨⋯ 3 ⋯ 2 ⋯ 5 ⋯⟩」, we need

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

This however matches ⛔「⟨⋯ ᵃb ⋯⟩, |a-b|=3」. It follows that 5 != [1st].

      ┌───┬───┬───┬───┬───┬───┐
      │5th│4th│3rd│2nd│1st│0th│
      ╞═══╪═══╪═══╪═══╪═══╪═══╡
(2.4) │ 1 │ / │   │ / │ / │ / │
      └───┴───┴───┴───┴───┴───┘

Accordingly, we have 5 = [3rd]:

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

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

By ✅「min ⊢5⊣ = 2」, 2 is adjacent to 5. If 2 = [2nd], then we cannot avoid ⛔「⟨ ⁵ᵗʰa     ²ⁿᵈb ¹ˢᵗc   ⟩, (abc)₁₀ ≤ 132」. Therefore, 2 = [4th]:

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

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

Now, to avoid ⛔「⟨ ⁵ᵗʰa     ²ⁿᵈb ¹ˢᵗc   ⟩, (abc)₁₀ ≤ 132」, there are two possibilities:

      ┌───┬───┬───┬───┬───┬───┐
      │5th│4th│3rd│2nd│1st│0th│
      ╞═══╪═══╪═══╪═══╪═══╪═══╡
(3.1) │ 1 │ 2 │ 5 │ 3 │ 4 │   │
      ├───┼───┼───┼───┼───┼───┤
(3.2) │ 1 │ 2 │ 5 │ 4 │   │   │
      └───┴───┴───┴───┴───┴───┘

If (3.1) holds, then we match ⛔「⟨⋯ ᵃb ⋯⟩, |a-b|=3」. Therefore, (3.2) holds instead.

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

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

Finally, using ⛔「⟨⋯ ᵃb ⋯⟩, |a-b|=3」 again, we finish by

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

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

Q.E.D.

#125034_v2.13