The New Sudoku Players' Forum

[ArkieTech]

Code: Select all

 *-----------*
 |.5.|...|6..|
 |...|.3.|..2|
 |.41|2..|5..|
 |---+---+---|
 |.13|.4.|.8.|
 |8..|.6.|3..|
 |...|1..|.7.|
 |---+---+---|
 |2..|8..|...|
 |..5|..6|...|
 |...|9..|..4|
 *-----------*


Play/Print this puzzle online

[SteveG48]

Code: Select all

 *--------------------------------------------------*
 | 3    5    2    | 4    7    1    | 6    9    8    |
 | 7    9-8 a89   | 6    3    5    | 14   14   2    |
 | 6    4    1    | 2    9    8    | 5    3    7    |
 *----------------+----------------+----------------|
 | 5    1    3    | 7    4    2    | 9    8    6    |
 | 8   f27   47   | 5    6    9    | 3   e24   1    |
 | 9    26   46   | 1    8    3    | 24   7    5    |
 *----------------+----------------+----------------|
 | 2    679  679  | 8    15   4    | 17   56   3    |
 | 4   f78   5    | 3    12   6    | 78  d12   9    |
 | 1    3   b6-8  | 9    25   7    |c28   56   4    |
 *--------------------------------------------------*


(8)r2c3 = r9c3 - (8=2)r9c7 - r8c8 = r5c8 - (2=78)r58c2 => -8 r2c2,r9c3 ; stte

[Leren]

Code: Select all

*--------------------------------------------------------------*
| 3     5     2      | 4     7     1      | 6     9     8      |
| 7     89    89     | 6     3     5      | 14    14    2      |
| 6     4     1      | 2     9     8      | 5     3     7      |
|--------------------+--------------------+--------------------|
| 5     1     3      | 7     4     2      | 9     8     6      |
| 8     27   a47     | 5     6     9      | 3    b24    1      |
| 9     26    46     | 1     8     3      | 24    7     5      |
|--------------------+--------------------+--------------------|
| 2     679   69-7   | 8     15    4      |d17    56    3      |
| 4     78    5      | 3     12    6      | 78   c12    9      |
| 1     3     68     | 9     25    7      | 28    56    4      |
*--------------------------------------------------------------*

XY Chain : (7=4) r5c3 - (4=2) r5c8 - (2=1) r8c8 - (1=7) r7c7 => - 7 r7c3; stte

Leren

[SteveG48]

Code: Select all

 *--------------------------------------------------*
 | 3    5    2    | 4    7    1    | 6    9    8    |
 | 7    89   89   | 6    3    5    | 14   14   2    |
 | 6    4    1    | 2    9    8    | 5    3    7    |
 *----------------+----------------+----------------|
 | 5    1    3    | 7    4    2    | 9    8    6    |
 | 8    27   47   | 5    6    9    | 3    24   1    |
 | 9    26   46   | 1    8    3    | 24   7    5    |
 *----------------+----------------+----------------|
 | 2   a679 b69-7 | 8   c15   4    |c17  c56   3    |
 | 4    78   5    | 3    12   6    | 78   12   9    |
 | 1    3    68   | 9    25   7    | 28   56   4    |
 *--------------------------------------------------*


OK, let's see if I get it right this time:

BUG+2: (7)r7c2 = (6)r7c3 - (6=157)r7c578 => -7 r7c3 ; stte

[daj95376]

Code: Select all

 *--------------------------------------------------*
 | 3    5    2    | 4    7    1    | 6    9    8    |
 | 7    89   89   | 6    3    5    | 14   14   2    |
 | 6    4    1    | 2    9    8    | 5    3    7    |
 *----------------+----------------+----------------|
 | 5    1    3    | 7    4    2    | 9    8    6    |
 | 8    27   47   | 5    6    9    | 3    24   1    |
 | 9    26   46   | 1    8    3    | 24   7    5    |
 *----------------+----------------+----------------|
 | 2   a679 b69-7 | 8   c15   4    |c17  c56   3    |
 | 4    78   5    | 3    12   6    | 78   12   9    |
 | 1    3    68   | 9    25   7    | 28   56   4    |
 *--------------------------------------------------*


OK, let's see if I get it right this time:

BUG+2: (7)r7c2 = (6)r7c3 - (6=157)r7c578 => -7 r7c3 ; stte

Too much logic.

BUG+2: (7)r7c2 = (6)r7c3 => -6 r7c2; -7 r7c3

_

[SteveG48]

At least I got the BUG part right this time. That's progress!

[ArkieTech]

Code: Select all

 *--------------------------------------------------*
 | 3    5    2    | 4    7    1    | 6    9    8    |
 | 7    89   89   | 6    3    5    | 14   14   2    |
 | 6    4    1    | 2    9    8    | 5    3    7    |
 *----------------+----------------+----------------|
 | 5    1    3    | 7    4    2    | 9    8    6    |
 | 8    27   47   | 5    6    9    | 3    24   1    |
 | 9    26   46   | 1    8    3    | 24   7    5    |
 *----------------+----------------+----------------|
 | 2   a679 b69-7 | 8   c15   4    |c17  c56   3    |
 | 4    78   5    | 3    12   6    | 78   12   9    |
 | 1    3    68   | 9    25   7    | 28   56   4    |
 *--------------------------------------------------*


OK, let's see if I get it right this time:

BUG+2: (7)r7c2 = (6)r7c3 - (6=157)r7c578 => -7 r7c3 ; stte

Too much logic.

BUG+2: (7)r7c2 = (6)r7c3 => -6 r7c2; -7 r7c3

_

Why the parenthesis?

Bug+2:7r7c2=6r7c3 => -6r7c2 -7r7c3

doesn't ; indicate another step?

[bat999]

Code: Select all

.---------------.----------.------------.
| 3  5      2   | 4  7   1 | 6   9    8 |
| 7  89     89  | 6  3   5 | 14  14   2 |
| 6  4      1   | 2  9   8 | 5   3    7 |
:---------------+----------+------------:
| 5  1      3   | 7  4   2 | 9   8    6 |
| 8  X27    47  | 5  6   9 | 3   24   1 |
| 9  A26    46  | 1  8   3 | 24  7    5 |
:---------------+----------+------------:
| 2  d79-6  679 | 8  15  4 | 17  B56  3 |
| 4  c78    5   | 3  12  6 | 78  12   9 |
| 1  3      b68 | 9  25  7 | 28  a56  4 |
'---------------'----------'------------'

A=r6c2, B=r7c8, X=r5c2
A<>6->X=7
B<>6=>r9c8=6=>r9c3=8=>r8c2=7->X=2
=> A or B is 6, r7c2 is not 6
=> -6 r7c2; stte

[Leren]

bat999 wrote:

A<>6->X=7
B<>6=>r9c8=6=>r9c3=8=>r8c2=7->X=2
=> A or B is 6, r7c2 is not 6
=> -6 r7c2; stte

You don't need cells a and B to prove - 6 r7c2. In your parlance you could just as easily write :

A<>6->X=7
b <> 6 => c=7 => X=2
=> A or b is 6, r7c2 is not 6

or

A<> 6 => X=7 => c=8
b<> 6 => c=7
=> A or b is 6, r7c2 is not 6

Either way, in more standard terminology this is an XY chain :

Code: Select all

(6=2) r6c2 - (2=7) r5c2 - (7=8) r8c2 - (8=6) r9c3 => - 6 r8c2
        A           X             c            b

Leren

[bat999]

... don't need cells a and B...

Yes, could have used r9c3 for B instead of r7c8.
But r7c8 did the job, no need to mess about looking for other squares that can do it too.

...this is an XY chain...

It may be a chain to you, but it's a pair of tests to me.

[daj95376]

Why the parenthesis?

Bug+2:7r7c2=6r7c3 => -6r7c2 -7r7c3

doesn't ; indicate another step?

After all of the discussion on proper Eureka notation, maybe SteveG48 decided to use parenthesis to keep from being criticized. I just copied the appropriate portion out of laziness.

As for (;), I also use it to partition eliminations. Yes, it's probably better that I use something else.

Bug+2: (7)r7c2=(6)r7c3 => -6 r7c2 & -7 r7c3

_

[gurth]

[gurth]

BUG+2: (7)r7c2 = (6)r7c3 => -6 r7c2; -7 r7c3

_



Why the parenthesis?

Bug+2:7r7c2=6r7c3 => -6r7c2 -7r7c3

Why indeed? I already think the current notation, 7r7c2, being 40% redundant, is laughable; now writing (7)r7c2, being over 50% redundant, is scaling new heights of absurdity. What became of Maria45 with her 9k9 notation?
- By all means use rc when they serve some purpose, as for group notation.
AIC is full of bad ideas. writing '=' for '|' still causes problems, after all these years. People should NOT adopt existing, COMMON, well-established symbols like '=" for other, entirely different meanings, especially when entirely adequate symbols already exist.
I'll write "Bug+2:7r7c2=6r7c3 => -6r7c2 -7r7c3" as 'Bug+2: 772|673 ; -672, -773.'

[David P Bird]

writing '=' for '|' still causes problems, after all these years.

Gurth, you imply that '|' is the generally accepted symbol for the Boolean OR operator. A quick Google search doesn't support that. In a proportionally spaced font '=' is a better symbol and nicely complements the '-' symbol adopted for NAND (which otherwise would have required using the combined symbols for NOT AND).

[Ngisa]

Code: Select all

+-----------+--------+---------+
| 3 5   2   | 4 7  1 | 6  9  8 |
| 7 89  89  | 6 3  5 | 14 14 2 |
| 6 4   1   | 2 9  8 | 5  3  7 |
+-----------+--------+---------+
| 5 1   3   | 7 4  2 | 9  8  6 |
| 8 c27  47  | 5 6  9 | 3  24 1 |
| 9 d26  4-6  | 1 8  3 | 24 7  5 |
+-----------+--------+---------+
| 2 679 679 | 8 15 4 | 17 56 3 |
| 4 b78  5   | 3 12 6 | 78 12 9 |
| 1 3   a68  | 9 25 7 | 28 56 4 |
+-----------+--------+---------+


Seems many XY Chains
(6=8)r9c3-(8=7)r8c2-(7=2)r5c2-(2=6)r6c2 => -6r6c3; stte.