Rearrange the digits in ⟨1263045⟩ to meet the rules below.
⟨6th 5th 4th 3rd 2nd 1st 0th⟩
✅Match
Jump(0,1) = 4
Jump(1,6) ≥ 3
min ⊢5⊣ = 3
⟨⋯ 3 ⋯ 5 ⋯⟩
⛔Avoid
min ⊢4⊣ ≥ 2
⟨ ⁶ᵗʰa ²ⁿᵈb ¹ˢᵗc ⟩, (abc)₁₀ ≥ 123
#125034_v2.6
┌───┬───┬───┬───┬───┬───┬───┐ │6th│5th│4th│3rd│2nd│1st│0th│▒ ╞═══╪═══╪═══╪═══╪═══╪═══╪═══╡▒ Step 1 │ 0 │ │ │ │ │ │ │▒ ├───┼───┼───┼───┼───┼───┼───┤▒ Step 2 │ 0 │ │ │ │ │ 1 │ │▒ ├───┼───┼───┼───┼───┼───┼───┤▒ Step 3 │ 0 │ 6 │ │ │ │ 1 │ │▒ ├───┼───┼───┼───┼───┼───┼───┤▒ Step 4 │ 0 │ 6 │ 3 │ │ │ 1 │ │▒ ├───┼───┼───┼───┼───┼───┼───┤▒ Step 5 │ 0 │ 6 │ 3 │ 5 │ │ 1 │ │▒ ├───┼───┼───┼───┼───┼───┼───┤▒ Step 6 │ 0 │ 6 │ 3 │ 5 │ 4 │ 1 │ │▒ ├───┼───┼───┼───┼───┼───┼───┤▒ Step 7 │ 0 │ 6 │ 3 │ 5 │ 4 │ 1 │ 2 │▒ └───┴───┴───┴───┴───┴───┴───┘▒ ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ Proof of 2024-09-17 Q1(m=6) ═══════════════════════════ Notation: if nth -> a, then we write [nth] = a. In order to avoid ⛔「⟨ ⁶ᵗʰa ²ⁿᵈb ¹ˢᵗc ⟩, (abc)₁₀ ≥ 123」, we need [6th] = 1|0. (1) We claim that [6th] = 0 actually. ------------------------------ Suppose this is not the case. Then [6th] = 1. By ✅「Jump(0,1) = 4」, we have [1st] = 0 as well: ┌───┬───┬───┬───┬───┬───┬───┐ │ 6▲│5th│4th│3rd│2nd│ 1▲│0th│ ╞═══╪═══╪═══╪═══╪═══╪═══╪═══╡ │ 1 │ │ │ │ │ 0 │ │ └───┴───┴───┴───┴───┴───┴───┘ --- Idle --- ┌───┬───┬───┬───┬───┬───┬───┐ │ │ 2 │ 6 │ 3 │ │ 4 │ 5 │ └───┴───┴───┴───┴───┴───┴───┘ Then, observe that to avoid ⛔「⟨ ⁶ᵗʰa ²ⁿᵈb ¹ˢᵗc ⟩, (abc)₁₀ ≥ 123」, we need [2nd] = 2: ┌───┬───┬───┬───┬───┬───┬───┐ │6th│5th│4th│3rd│ 2▲│1st│0th│ ╞═══╪═══╪═══╪═══╪═══╪═══╪═══╡ │ 1 │ │ │ │ 2 │ 0 │ │ └───┴───┴───┴───┴───┴───┴───┘ It follows that there is only one way to match ✅「Jump(1,6) ≥ 3」: ┌───┬───┬───┬───┬───┬───┬───┐ │6th│5th│4th│3rd│2nd│1st│ 0▲│ ╞═══╪═══╪═══╪═══╪═══╪═══╪═══╡ │ 1 │ │ │ │ 2 │ 0 │ 6 │ └───┴───┴───┴───┴───┴───┴───┘ --- Idle --- ┌───┬───┬───┬───┬───┬───┬───┐ │ │ │ │ 3 │ │ 4 │ 5 │ └───┴───┴───┴───┴───┴───┴───┘ and only one way to avoid ⛔「min ⊢4⊣ ≥ 2」: ┌───┬───┬───┬───┬───┬───┬───┐ │6th│ 5▲│4th│3rd│2nd│1st│0th│ ╞═══╪═══╪═══╪═══╪═══╪═══╪═══╡ │ 1 │ 4 │ │ │ 2 │ 0 │ 6 │ └───┴───┴───┴───┴───┴───┴───┘ Using ✅「⟨⋯ 3 ⋯ 5 ⋯⟩」, we reach ┌───┬───┬───┬───┬───┬───┬───┐ │6th│5th│ 4▲│ 3▲│2nd│1st│0th│ ╞═══╪═══╪═══╪═══╪═══╪═══╪═══╡ │ 1 │ 4 │ 3 │ 5 │ 2 │ 0 │ 6 │ └───┴───┴───┴───┴───┴───┴───┘ It is a contradiction, however, as we do not match ✅「min ⊢5⊣ = 3」. ------------------------------ We have verified our claim in (1). Accordingly, we get ┌───┬───┬───┬───┬───┬───┬───┐ │ 6■│5th│4th│3rd│2nd│1st│0th│▒ ╞═══╪═══╪═══╪═══╪═══╪═══╪═══╡▒ Step 1 │ 0 │ │ │ │ │ │ │▒ └───┴───┴───┴───┴───┴───┴───┘▒ ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ --- Idle --- ┌───┬───┬───┬───┬───┬───┬───┐ │ 1 │ 2 │ 6 │ 3 │ │ 4 │ 5 │ └───┴───┴───┴───┴───┴───┴───┘ Plainly, by ✅「Jump(0,1) = 4」 and ✅「Jump(1,6) ≥ 3」, we then get ┌───┬───┬───┬───┬───┬───┬───┐ │6th│ 5■│4th│3rd│2nd│ 1■│0th│▒ ╞═══╪═══╪═══╪═══╪═══╪═══╪═══╡▒ │ 0 │ │ │ │ │ │ │▒ ├───┼───┼───┼───┼───┼───┼───┤▒ Step 2 │ 0 │ │ │ │ │ 1 │ │▒ ├───┼───┼───┼───┼───┼───┼───┤▒ Step 3 │ 0 │ 6 │ │ │ │ 1 │ │▒ └───┴───┴───┴───┴───┴───┴───┘▒ ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ --- Idle --- ┌───┬───┬───┬───┬───┬───┬───┐ │ │ 2 │ │ 3 │ │ 4 │ 5 │ └───┴───┴───┴───┴───┴───┴───┘ Next, note that by combining ✅「min ⊢5⊣ = 3」 with ✅「⟨⋯ 3 ⋯ 5 ⋯⟩」, we have the following required pattern: (2) ⟨⋯ 3 5 ⋯⟩ There are two possibilities: ┌───┬───┬───┬───┬───┬───┬───┐ │6th│5th│4th│3rd│2nd│1st│0th│ ╞═══╪═══╪═══╪═══╪═══╪═══╪═══╡ (2.1) │ 0 │ 6 │ │ 3 │ 5 │ 1 │ │ ├───┼───┼───┼───┼───┼───┼───┤ (2.2) │ 0 │ 6 │ 3 │ 5 │ │ 1 │ │ └───┴───┴───┴───┴───┴───┴───┘ In view of ✅「min ⊢5⊣ = 3」, case (2.1) does not hold. So, case (2.2) holds, and we get ┌───┬───┬───┬───┬───┬───┬───┐ │6th│5th│ 4■│ 3■│2nd│1st│0th│▒ ╞═══╪═══╪═══╪═══╪═══╪═══╪═══╡▒ │ 0 │ 6 │ │ │ │ 1 │ │▒ ├───┼───┼───┼───┼───┼───┼───┤▒ Step 4 │ 0 │ 6 │ 3 │ │ │ 1 │ │▒ ├───┼───┼───┼───┼───┼───┼───┤▒ Step 5 │ 0 │ 6 │ 3 │ 5 │ │ 1 │ │▒ └───┴───┴───┴───┴───┴───┴───┘▒ ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ --- Idle --- ┌───┬───┬───┬───┬───┬───┬───┐ │ │ 2 │ │ │ │ 4 │ │ └───┴───┴───┴───┴───┴───┴───┘ To match ✅「min ⊢5⊣ = 3」, we cannot place 2 next to 5. Therefore, we finish by ┌───┬───┬───┬───┬───┬───┬───┐ │6th│5th│4th│3rd│ 2■│1st│ 0■│▒ ╞═══╪═══╪═══╪═══╪═══╪═══╪═══╡▒ │ 0 │ 6 │ 3 │ 5 │ │ 1 │ │▒ ├───┼───┼───┼───┼───┼───┼───┤▒ Step 6 │ 0 │ 6 │ 3 │ 5 │ 4 │ 1 │ │▒ ├───┼───┼───┼───┼───┼───┼───┤▒ Step 7 │ 0 │ 6 │ 3 │ 5 │ 4 │ 1 │ 2 │▒ └───┴───┴───┴───┴───┴───┴───┘▒ ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ --- Idle --- ┌───┬───┬───┬───┬───┬───┬───┐ │ │ │ │ │ │ │ │ └───┴───┴───┴───┴───┴───┴───┘ Q.E.D. #125034_v2.6
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