Rearrange the digits in ⟨125034⟩ to meet the rules below.
⟨ ⁵ᵗʰ▨ ⁴ᵗʰ▨ ³ʳᵈ▨ ²ⁿᵈ▨ ¹ˢᵗ▨ ⁰ᵗʰ▨ ⟩
✅Match
Jump(0,4) = 2
⟨⋯ Perm(2,3) ⋯⟩
⟨ ⁴ᵗʰa ²ⁿᵈb ¹ˢᵗc ⟩, (abc)₁₀ ≥ 420
2nd → a, 0th → b, a+b=7
⛔Avoid
⟨⋯ ᵃb ⋯⟩, ab=6+7n
#125034_v2.15
┌───┬───┬───┬───┬───┬───┐
│5th│4th│3rd│2nd│1st│0th│▒
╞═══╪═══╪═══╪═══╪═══╪═══╡▒
Step 1 │ │ 4 │ │ │ │ │▒
├───┼───┼───┼───┼───┼───┤▒
Step 2 │ │ 4 │ │ │ 0 │ │▒
├───┼───┼───┼───┼───┼───┤▒
Step 3 │ │ 4 │ │ 2 │ 0 │ │▒
├───┼───┼───┼───┼───┼───┤▒
Step 4 │ │ 4 │ │ 2 │ 0 │ 5 │▒
├───┼───┼───┼───┼───┼───┤▒
Step 5 │ │ 4 │ 3 │ 2 │ 0 │ 5 │▒
├───┼───┼───┼───┼───┼───┤▒
Step 6 │ 1 │ 4 │ 3 │ 2 │ 0 │ 5 │▒
└───┴───┴───┴───┴───┴───┘▒
▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
Proof of 2026-10-20 WR
══════════════════════
Notation: if nth -> a, then we write [nth] = a.
By ✅「⟨ ⁴ᵗʰa ²ⁿᵈb ¹ˢᵗc ⟩, (abc)₁₀ ≥ 420」, we have
(1) [4th] = 4 or 5.
If it is 5, then we would match ⛔「⟨⋯ ᵃb ⋯⟩, ab=6+7n」, which is not allowed. Therefore, [4th] = 4:
┌───┬───┬───┬───┬───┬───┐
│5th│ 4■│3rd│2nd│1st│0th│▒
╞═══╪═══╪═══╪═══╪═══╪═══╡▒
Step 1 │ │ 4 │ │ │ │ │▒
└───┴───┴───┴───┴───┴───┘▒
▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
--- Idle ---
┌───┬───┬───┬───┬───┬───┐
│ 1 │ 2 │ 5 │ 0 │ 3 │ │
└───┴───┴───┴───┴───┴───┘
Then, in view of ✅「Jump(0,4) = 2」, plainly we have [1st] = 0:
┌───┬───┬───┬───┬───┬───┐
│5th│4th│3rd│2nd│ 1■│0th│▒
╞═══╪═══╪═══╪═══╪═══╪═══╡▒
│ │ 4 │ │ │ │ │▒
├───┼───┼───┼───┼───┼───┤▒
Step 2 │ │ 4 │ │ │ 0 │ │▒
└───┴───┴───┴───┴───┴───┘▒
▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
--- Idle ---
┌───┬───┬───┬───┬───┬───┐
│ 1 │ 2 │ 5 │ │ 3 │ │
└───┴───┴───┴───┴───┴───┘
Now, to match ✅「2nd → a, 0th → b, a+b=7」, we need
(2) {[2nd], [0th]} = {2,5}.
Combining this with ✅「⟨⋯ Perm(2,3) ⋯⟩」, we finish by
┌───┬───┬───┬───┬───┬───┐
│ 5■│4th│ 3■│2nd│ 1■│ 0■│▒
╞═══╪═══╪═══╪═══╪═══╪═══╡▒
│ │ 4 │ │ │ 0 │ │▒
├───┼───┼───┼───┼───┼───┤▒
Step 3 │ │ 4 │ │ 2 │ 0 │ │▒
├───┼───┼───┼───┼───┼───┤▒
Step 4 │ │ 4 │ │ 2 │ 0 │ 5 │▒
├───┼───┼───┼───┼───┼───┤▒
Step 5 │ │ 4 │ 3 │ 2 │ 0 │ 5 │▒
├───┼───┼───┼───┼───┼───┤▒
Step 6 │ 1 │ 4 │ 3 │ 2 │ 0 │ 5 │▒
└───┴───┴───┴───┴───┴───┘▒
▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
--- Idle ---
┌───┬───┬───┬───┬───┬───┐
│ │ │ │ │ │ │
└───┴───┴───┴───┴───┴───┘
Q.E.D.
#125034_v2.15