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2024-12-03 Q1(m=6)

Rearrange the digits in ⟨1263045⟩ to meet the rules below.

⟨6th 5th 4th 3rd 2nd 1st 0th⟩

✅Match
5th → a, 0th → b, |a-b|=1
⟨? 2 ⋯ (?+3) ⋯ 6 ⋯⟩ (?≠2)
Jump(2,3) ≥ 2

⛔Avoid
⟨? ⋯ 4 ⋯ (?+5) ⋯⟩

#125034_v2.7


       ┌───┬───┬───┬───┬───┬───┬───┐
       │6th│5th│4th│3rd│2nd│1st│0th│▒
       ╞═══╪═══╪═══╪═══╪═══╪═══╪═══╡▒
Step 1 │   │ 2 │   │   │   │   │   │▒
       ├───┼───┼───┼───┼───┼───┼───┤▒
Step 2 │ 0 │ 2 │   │   │   │   │   │▒
       ├───┼───┼───┼───┼───┼───┼───┤▒
Step 3 │ 0 │ 2 │   │   │   │   │ 1 │▒
       ├───┼───┼───┼───┼───┼───┼───┤▒
Step 4 │ 0 │ 2 │   │   │ 3 │   │ 1 │▒
       ├───┼───┼───┼───┼───┼───┼───┤▒
Step 5 │ 0 │ 2 │   │   │ 3 │ 6 │ 1 │▒
       ├───┼───┼───┼───┼───┼───┼───┤▒
Step 6 │ 0 │ 2 │ 5 │   │ 3 │ 6 │ 1 │▒
       ├───┼───┼───┼───┼───┼───┼───┤▒
Step 7 │ 0 │ 2 │ 5 │ 4 │ 3 │ 6 │ 1 │▒
       └───┴───┴───┴───┴───┴───┴───┘▒
        ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒

Proof of 2024-12-03 Q1(m=6)
═══════════════════════════

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

Our first step follows from ✅「⟨? 2 ⋯ (?+3) ⋯ 6 ⋯⟩ (?≠2)」:

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

--- Idle ---
┌───┬───┬───┬───┬───┬───┬───┐
│ 1 │   │ 6 │ 3 │ 0 │ 4 │ 5 │
└───┴───┴───┴───┴───┴───┴───┘

That pattern also implies

(1) [6th] = 0|1|3.

(2) We show that [6th] = 0 actually.

------------------------------

(2.1) For, if [6th] = 3:

┌───┬───┬───┬───┬───┬───┬───┐
│ 6▲│5th│4th│3rd│2nd│1st│0th│
╞═══╪═══╪═══╪═══╪═══╪═══╪═══╡
│ 3 │ 2 │   │   │   │   │   │
└───┴───┴───┴───┴───┴───┴───┘

then we cannot match ✅「Jump(2,3) ≥ 2」.

(2.2) Else if [6th] = 1:

┌───┬───┬───┬───┬───┬───┬───┐
│ 6▲│5th│4th│3rd│2nd│1st│0th│
╞═══╪═══╪═══╪═══╪═══╪═══╪═══╡
│ 1 │ 2 │   │   │   │   │   │
└───┴───┴───┴───┴───┴───┴───┘

then we cannot avoid ⛔「⟨? ⋯ 4 ⋯ (?+5) ⋯⟩」 and match ✅「⟨? 2 ⋯ (?+3) ⋯ 6 ⋯⟩ (?≠2)」 at the same time.

------------------------------

We have verified (2). Accordingly, we get

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

--- Idle ---
┌───┬───┬───┬───┬───┬───┬───┐
│ 1 │   │ 6 │ 3 │   │ 4 │ 5 │
└───┴───┴───┴───┴───┴───┴───┘

Therefore, by ✅「⟨? 2 ⋯ (?+3) ⋯ 6 ⋯⟩ (?≠2)」, we have the following required pattern:

(3) ⟨0 2 ⋯ 3 ⋯ 6 ⋯⟩.

In particular, there is at least one digit at the right of 3. Hence, to match ✅「5th → a, 0th → b, |a-b|=1」, we need [0th] = 1:

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

--- Idle ---
┌───┬───┬───┬───┬───┬───┬───┐
│   │   │ 6 │ 3 │   │ 4 │ 5 │
└───┴───┴───┴───┴───┴───┴───┘

Then, combining ✅「Jump(2,3) ≥ 2」 with (3), we get

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

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

Finally, to avoid ⛔「⟨? ⋯ 4 ⋯ (?+5) ⋯⟩」, we finish by

       ┌───┬───┬───┬───┬───┬───┬───┐
       │6th│5th│ 4■│ 3■│2nd│1st│0th│▒
       ╞═══╪═══╪═══╪═══╪═══╪═══╪═══╡▒
       │ 0 │ 2 │   │   │ 3 │ 6 │ 1 │▒
       ├───┼───┼───┼───┼───┼───┼───┤▒
Step 6 │ 0 │ 2 │ 5 │   │ 3 │ 6 │ 1 │▒
       ├───┼───┼───┼───┼───┼───┼───┤▒
Step 7 │ 0 │ 2 │ 5 │ 4 │ 3 │ 6 │ 1 │▒
       └───┴───┴───┴───┴───┴───┴───┘▒
        ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒

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

Q.E.D.

#125034_v2.7