Rearrange the digits in ⟨125034⟩ to meet the rules below.
⟨ ⁵ᵗʰ▨ ⁴ᵗʰ▨ ³ʳᵈ▨ ²ⁿᵈ▨ ¹ˢᵗ▨ ⁰ᵗʰ▨ ⟩
✅Match
4 ∾ 5
0 ∾ 3
⛔Avoid
3 ∾ 5
⟨ ³ʳᵈa ²ⁿᵈb ⟩, (ab)₁₀ ≤ 20
#125034_v2.12
┌───┬───┬───┬───┬───┬───┐
│5th│4th│3rd│2nd│1st│0th│▒
╞═══╪═══╪═══╪═══╪═══╪═══╡▒
Step 1 │ │ │ 2 │ │ │ │▒
├───┼───┼───┼───┼───┼───┤▒
Step 2 │ │ │ 2 │ 1 │ │ │▒
├───┼───┼───┼───┼───┼───┤▒
Step 3 │ │ │ 2 │ 1 │ 0 │ │▒
├───┼───┼───┼───┼───┼───┤▒
Step 4 │ │ │ 2 │ 1 │ 0 │ 3 │▒
├───┼───┼───┼───┼───┼───┤▒
Step 5 │ │ 5 │ 2 │ 1 │ 0 │ 3 │▒
├───┼───┼───┼───┼───┼───┤▒
Step 6 │ 4 │ 5 │ 2 │ 1 │ 0 │ 3 │▒
└───┴───┴───┴───┴───┴───┘▒
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Proof of 2026-02-10 Q1(v=0)
═══════════════════════════
Notation: if nth -> a, then we write [nth] = a.
To avoid ⛔「⟨ ³ʳᵈa ²ⁿᵈb ⟩, (ab)₁₀ ≤ 20」, we need
(1) [3rd] = 2 | 3 | 4 | 5.
On the other hand, to avoid ⛔「3 ∾ 5」 and match ✅「4 ∾ 5」 at the same time, we need
(2.1) 3 and 5 are not in the same circle; and
(2.2) 3 and 4 are not in the same circle.
Applying them to (1), we get [3rd] = 2|3. If [3rd] = 3, then we cannot match ✅「0 ∾ 3」. Therefore, [3rd] = 2:
┌───┬───┬───┬───┬───┬───┐
│5th│4th│ 3■│2nd│1st│0th│▒
╞═══╪═══╪═══╪═══╪═══╪═══╡▒
Step 1 │ │ │ 2 │ │ │ │▒
└───┴───┴───┴───┴───┴───┘▒
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--- Idle ---
┌───┬───┬───┬───┬───┬───┐
│ 1 │ │ 5 │ 0 │ 3 │ 4 │
└───┴───┴───┴───┴───┴───┘
Next, we determine what [2nd] is. In view of (2.1) and (2.2), it is not 5 or 4. To match ✅「0 ∾ 3」, it is not 3. To avoid ⛔「⟨ ³ʳᵈa ²ⁿᵈb ⟩, (ab)₁₀ ≤ 20」, it is not 0. Therefore, [2nd] = 1:
┌───┬───┬───┬───┬───┬───┐
│5th│4th│3rd│ 2■│1st│0th│▒
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│ │ │ 2 │ │ │ │▒
├───┼───┼───┼───┼───┼───┤▒
Step 2 │ │ │ 2 │ 1 │ │ │▒
└───┴───┴───┴───┴───┴───┘▒
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--- Idle ---
┌───┬───┬───┬───┬───┬───┐
│ │ │ 5 │ 0 │ 3 │ 4 │
└───┴───┴───┴───┴───┴───┘
Using the same reasoning, we have [1st] = 0:
┌───┬───┬───┬───┬───┬───┐
│5th│4th│3rd│2nd│ 1■│0th│▒
╞═══╪═══╪═══╪═══╪═══╪═══╡▒
│ │ │ 2 │ 1 │ │ │▒
├───┼───┼───┼───┼───┼───┤▒
Step 3 │ │ │ 2 │ 1 │ 0 │ │▒
└───┴───┴───┴───┴───┴───┘▒
▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
--- Idle ---
┌───┬───┬───┬───┬───┬───┐
│ │ │ 5 │ │ 3 │ 4 │
└───┴───┴───┴───┴───┴───┘
Then, for [0th], in view of (2.1) and (2.2), it has to be 3:
┌───┬───┬───┬───┬───┬───┐
│5th│4th│3rd│2nd│1st│ 0■│▒
╞═══╪═══╪═══╪═══╪═══╪═══╡▒
│ │ │ 2 │ 1 │ 0 │ │▒
├───┼───┼───┼───┼───┼───┤▒
Step 4 │ │ │ 2 │ 1 │ 0 │ 3 │▒
└───┴───┴───┴───┴───┴───┘▒
▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
--- Idle ---
┌───┬───┬───┬───┬───┬───┐
│ │ │ 5 │ │ │ 4 │
└───┴───┴───┴───┴───┴───┘
Finally, to match ✅「4 ∾ 5」, we finish by
┌───┬───┬───┬───┬───┬───┐
│ 5■│ 4■│3rd│2nd│1st│0th│▒
╞═══╪═══╪═══╪═══╪═══╪═══╡▒
│ │ │ 2 │ 1 │ 0 │ 3 │▒
├───┼───┼───┼───┼───┼───┤▒
Step 5 │ │ 5 │ 2 │ 1 │ 0 │ 3 │▒
├───┼───┼───┼───┼───┼───┤▒
Step 6 │ 4 │ 5 │ 2 │ 1 │ 0 │ 3 │▒
└───┴───┴───┴───┴───┴───┘▒
▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
--- Idle ---
┌───┬───┬───┬───┬───┬───┐
│ │ │ │ │ │ │
└───┴───┴───┴───┴───┴───┘
Q.E.D.
#125034_v2.12