The New Sudoku Players' Forum

by **ArkieTech** » Sun Jun 09, 2019 10:25 am

Code: Select all: *-----------* |...|7..|.5.| |..2|...|7..| |.6.|.4.|..3| |---+---+---| |7..|5..|.6.| |..4|.1.|2..| |...|..4|...| |---+---+---| |.1.|.2.|.4.| |5..|6..|9..| |..3|...|...| *-----------*

Play/Print this puzzle online

by **Leren** » Sun Jun 09, 2019 10:39 am

Code: Select all: *-------------------------------------* | 14 38 9 | 7 38 2 | 146 5 d46-1 | | 348 5 2 | 1 38 6 | 7 89 489 | | 18 6 7 | 9 4 5 |a18 2 3 | |-----------+----------+--------------| | 7 2 1 | 5 9 38 | 348 6 48 | | 6 389 4 | 38 1 7 | 2 89 5 | | 38 389 5 | 2 6 4 | 138 7 189 | |-----------+----------+--------------| | 9 1 6 | 38 2 38 | 5 4 7 | | 5 4 8 | 6 7 1 | 9 3 2 | | 2 7 3 | 4 5 9 |b68 1 c68 | *-------------------------------------*

H2 Wing: (1=8) r3c7 - r9c7 = (8-6) r9c9 = (6) r1c9 => - 1 r1c9; stte

Leren

by **eleven** » Sun Jun 09, 2019 11:35 am

Code: Select all: +----------------+----------------+----------------+ | 14 #38 9 | 7 #38 2 | 146 5 146 | |#38+4 5 2 | 1 #38 6 | 7 89 b489 | | 18 6 7 | 9 4 5 | 18 2 3 | +----------------+----------------+----------------+ | 7 2 1 | 5 9 38 | 348 6 48 | | 6 389 4 | 38 1 7 | 2 89 5 | |#38 #38+9 5 | 2 6 4 | 138 7 a189 | +----------------+----------------+----------------+ | 9 1 6 | 38 2 38 | 5 4 7 | | 5 4 8 | 6 7 1 | 9 3 2 | | 2 7 3 | 4 5 9 | 68 1 68 | +----------------+----------------+----------------+

BUG-lite 38: 4r2c1=9r6c2
4r2c1 == 9r6c2 - r6c9 = r2c9 => -4r2c9, stte

by **Ngisa** » Sun Jun 09, 2019 1:24 pm

Code: Select all: +--------------------+------------------+--------------------+ |c14 38 9 | 7 38 2 | 146 5 146 | |c348 5 2 | 1 38 6 | 7 89 b489 | |c18 6 7 | 9 4 5 |d18 2 3 | +--------------------+------------------+--------------------+ | 7 2 1 | 5 9 38 | 34-8 6 a48 | | 6 389 4 | 38 1 7 | 2 9-8 5 | |d38 389 5 | 2 6 4 |e138 7 19-8| +--------------------+------------------+--------------------+ | 9 1 6 | 38 2 38 | 5 4 7 | | 5 4 8 | 6 7 1 | 9 3 2 | | 2 7 3 | 4 5 9 | 68 1 68 | +--------------------+------------------+--------------------+

(8=4)r4c9 - r2c9 = (148)r123c1 - (8=13)r3c7&r6c1 - (13=8)r6c7 => - 8r4c7,r5c8, r6c9; stte

Clement

by **SteveG48** » Sun Jun 09, 2019 2:28 pm

Code: Select all: *---------------------------------------------------* |b14 38 9 | 7 38 2 | a146 5 a146 | | 348 5 2 | 1 38 6 | 7 89 489 | |b18 6 7 | 9 4 5 |ac18 2 3 | *----------------+----------------+-----------------| | 7 2 1 | 5 9 38 | 34-8 6 48 | | 6 389 4 | 38 1 7 | 2 89 5 | |b38 389 5 | 2 6 4 | c138 7 189 | *----------------+----------------+-----------------| | 9 1 6 | 38 2 38 | 5 4 7 | | 5 4 8 | 6 7 1 | 9 3 2 | | 2 7 3 | 4 5 9 | 6-8 1 68 | *---------------------------------------------------*

(8=146)b3p137 - (4=138)r136c1 - (3=18)r36c7 => -8 r49c7 ; stte

by **SteveG48** » Sun Jun 09, 2019 2:37 pm

Ngisa wrote:
Code: Select all
+--------------------+------------------+--------------------+ |c14 38 9 | 7 38 2 | 146 5 146 | |c348 5 2 | 1 38 6 | 7 89 b489 | |c18 6 7 | 9 4 5 |d18 2 3 | +--------------------+------------------+--------------------+ | 7 2 1 | 5 9 38 | 34-8 6 a48 | | 6 389 4 | 38 1 7 | 2 9-8 5 | |d38 389 5 | 2 6 4 |e138 7 19-8| +--------------------+------------------+--------------------+ | 9 1 6 | 38 2 38 | 5 4 7 | | 5 4 8 | 6 7 1 | 9 3 2 | | 2 7 3 | 4 5 9 | 68 1 68 | +--------------------+------------------+--------------------+

(8=4)r4c9 - r2c9 = (148)r123c1 - (8=13)r3c7&r6c1 - (13=8)r6c7 => - 8r4c7,r5c8, r6c9; stte

Clement

That's a beauty, Clement.

For the notation, I would suggest replacing (8=13)r3c7&r6c1 with (8=13)r3c7,r6c1. As written with the &, it says that both 1 and 3 are true in each of those two cells, which clearly isn't true. With the comma, it say that both 1 and 3 are true in that set of two cells, which is your intent. Also, the next term should be (1|3=8)r6c7.

by **SpAce** » Sun Jun 09, 2019 8:43 pm

SteveG48 wrote:
Ngisa wrote:(8=4)r4c9 - r2c9 = (148)r123c1 - (8=13)r3c7&r6c1 - (13=8)r6c7 => - 8r4c7,r5c8, r6c9; stte

That's a beauty, Clement.

Yes, the logic is very nice.

For the notation, I would suggest replacing (8=13)r3c7&r6c1 with (8=13)r3c7,r6c1. As written with the &, it says that both 1 and 3 are true in each of those two cells, which clearly isn't true. With the comma, it say that both 1 and 3 are true in that set of two cells, which is your intent. Also, the next term should be (1|3=8)r6c7.

Yep, but even those corrections don't make this link work: (148)r123c1 - (8=13)r3c7,r6c1. Some options to fix that:

(8=4)r4c9 - r2c9 = (41)r21c1 - (1=8)r3c1 - (8=13)r3c7,r6c1 - (1|3=8)r6c7
(8=4)r4c9 - r2c9 = (41,8)r213c1 - (8=13)r3c7,r6c1 - (1|3=8)r6c7
(8=4)r4c9 - r2c9 = (438)b1p427 - (8=13)r3c7,r6c1 - (1|3=8)r6c7

Then again, it's a waste of breath to mention these things. Clement obviously doesn't care.

by **Cenoman** » Sun Jun 09, 2019 9:16 pm

Yet another BUG-lite:

Code: Select all: +-------------------+-----------------+-------------------+ | 14 b38# 9 | 7 38 2 | 146 5 g46-1 | | b348# 5 2 | 1 38 6 | 7 89* 489* | | c18 6 7 | 9 4 5 | d18# 2 3 | +-------------------+-----------------+-------------------+ | 7 2 1 | 5 9 38 | 348 6 48 | | 6 389* 4 | 38 1 7 | 2 89* 5 | | 38 389* 5 | 2 6 4 | 138 7 a189*# | +-------------------+-----------------+-------------------+ | 9 1 6 | 38 2 38 | 5 4 7 | | 5 4 8 | 6 7 1 | 9 3 2 | | 2 7 3 | 4 5 9 | e68 1 f68 | +-------------------+-----------------+-------------------+

BUG-lite (89)r2c89,r56c2,b6p59 using mixed internal-externals {8r2c1==8r12c==1r6c9}
(1)r6c9==(8)r1c2|r2c1 - r3c1 = r3c7 - r9c7 = (8-6)r9c9 = (6)r1c9 => -1 r1c9; ste

by **SpAce** » Sun Jun 09, 2019 9:33 pm

Two more BUG-Lites...

Code: Select all: .-------------.------------.------------------------. | 14 38 9 | 7 38 2 | 46+1 5 46+1 | | 348 5 2 | 1 38 6 | 7 b89 b89#4 | | 18 6 7 | 9 4 5 | 18 2 3 | :-------------+------------+------------------------: | 7 2 1 | 5 9 38 | a48+3 6 a[4]-8+ | | 6 389 4 | 38 1 7 | 2 c(8)9 5 | | 38 389 5 | 2 6 4 | 138 7 189 | :-------------+------------+------------------------: | 9 1 6 | 38 2 38 | 5 4 7 | | 5 4 8 | 6 7 1 | 9 3 2 | | 2 7 3 | 4 5 9 | 68+ 1 68+ | '-------------'------------'------------------------'

BUG-Lite (468+13)r149c79 using mixed internal-external

(43)r4c97 == (49-8)r2c98 = (8)r5c8 => -8 r4c9; stte

and an uglier one: Show

by **eleven** » Sun Jun 09, 2019 10:22 pm

SpAce wrote:Clement obviously doesn't care.

No problem for me. I would have written it as almost xy-wing ...

... the link (48)r49c9 = r9c7 is less intuitive for me. (Why not (4=8)r4c9 - r9c9 = r9c7 ?)

or why not 4r4c9 = (4-3)r4c7 == (4-9)r2c9 = (9-8)r2c8 = 8r5c8
instead of (43)r4c97 == (49-8)r2c98 = (8)r5c8 ?

Make it more interesting for newcomers ?

by **SpAce** » Mon Jun 10, 2019 3:57 am

eleven wrote:
SpAce wrote:Clement obviously doesn't care.

No problem for me.

It's not a big problem for me either, as the logic is correct and easily seen anyway. I find it more irritating if lclste solutions are marked as stte and never fixed or even acknowledged after being notified. Obviously Clement doesn't care about that either.

I would have written it as almost xy-wing ...

Yes, that'd be nice:

Almost XY-Wing (81-13#8-38)r3c7,r6c7,r6c1:

(8)r6c7 = XY-Wing - (834)b1p724 = (4,8)r24c9 => -8 r4c7,r5c8,r6c9; stte

7x7 TM: Show

... the link (48)r49c9 = r9c7 is less intuitive for me.

Less intuitive than what? Actually incorrect notations? Or did you switch contexts? See, your own communications aren't always exactly intuitively interpretable either...

(Why not (4=8)r4c9 - r9c9 = r9c7 ?)

Mostly because I prefer combined nodes where possible (as a reader too), and partly because it was originally written as a kraken:

(4)r1c79
||
(3,8)r6c71 - r3c1 = r3c7 - r9c7 = (84)r94c9
||
(984)b6p953

Easier to see that way? I admit that it's not as intuitive when read from right to left, but obviously it works both ways. In fact, I'm wondering why I expanded the (3,8) link in the chain instead of writing:

(48)r49c9 = r9c7 - r3c7 = r3c1 - (8,3)r6c17 == (4)r1c79|(984)b6p953 => -4 r2c9; stte

Maybe that would be easier to read if reversed, but I see AICs as static and undirectional logic structures, so I don't really worry about it. A correct link must work both ways, and it's good practice to learn to read them both ways (especially if one way is less intuitive than the other).

Anyway, the bottom line is: I happen like compact AICs both as a reader and a writer, and that's that. If I want to be more explicit I rather write an uncompressed matrix to accompany the AIC:

6x6 TM: Show

or why not 4r4c9 = (4-3)r4c7 == (4-9)r2c9 = (9-8)r2c8 = 8r5c8
instead of (43)r4c97 == (49-8)r2c98 = (8)r5c8 ?

Because I much prefer the latter. Whom else should I aim to please when no one's paying me? Again, I have no problem providing a matrix POV if someone doesn't like my chain:

4x4 TM: Show

Make it more interesting for newcomers ?

What newcomers? That argument is getting old, and it's just as irrelevant as before (unfortunately). Besides, if that's really your concern, it's kind of curious that actually incorrect notations aren't a problem for you (as you stated above) but my valid compressions are. My chains aren't meant for newcomers, but be assured, if I have to write or teach someone to write newcomer-chains I can do that. Why would I, though, when there's no sign of newcomers and I enjoy neither writing nor reading obvious and tedious things for no reason? I only see veterans around who should have no problem understanding correct AICs no matter how they're written, and perhaps some might even enjoy figuring out some less than obvious things (and some don't, but can't please them all).

PS. Shouldn't you be happy that I've at least dropped the dreaded 3D notation? Don't you really have problems with anyone else's chains? I've explained my reasons before and they haven't changed, so this is all deja-vu. I could point out certain practices in everyone's chains that aren't that intuitive or readability-enhancing, or at least aren't in line with my personal preferences, but I don't care as long as they're correct. Similarly, I welcome any feedback that points out actual mistakes or inefficiencies in my logic or notations. I'm actually pretty good at changing my ways if I face good arguments. Someone's personal preferences don't really count, though, unless they happen to align with mine.

by **eleven** » Mon Jun 10, 2019 10:19 am

by **Cenoman** » Mon Jun 10, 2019 4:37 pm

I forgot to try one favourite:

Code: Select all: +-------------------+-----------------+-------------------+ | 14 38 9 | 7 38 2 | 46+1 5 16+4 | | 34+8 5 2 | 1 3-8 6 | 7 89 49+8 | | 18 6 7 | 9 4 5 | 18 2 3 | +-------------------+-----------------+-------------------+ | 7 2 1 | 5 9 38 | 34+8 6 48 | | 6 39+8 4 | 38 1 7 | 2 89 5 | | 38 89+3 5 | 2 6 4 | 13+8 7 19+8 | +-------------------+-----------------+-------------------+ | 9 1 6 | 38 2 38 | 5 4 7 | | 5 4 8 | 6 7 1 | 9 3 2 | | 2 7 3 | 4 5 9 | 68 1 68 | +-------------------+-----------------+-------------------+

BUG+9
(1)r1c7 - (168=4)r149c9 - (49=8)r2c89
(4)r1c9 - (49=8)r2c89
(8)r2c19
(8)b6p179|r5c2 - r5c8 = (8)r2c8
(3)r6c2 - r6c7 = (3-4)r4c7 = r1c7 - (49=8)r2c89
=>+8 r2c189 (-8 r2c5); ste

The New Sudoku Players' Forum

June 9, 2019

June 9, 2019

Re: June 9, 2019

Re: June 9, 2019

Re: June 9, 2019

Re: June 9, 2019

Re: June 9, 2019

Re: June 9, 2019

Re: June 9, 2019

Re: June 9, 2019

Re: June 9, 2019

Re: June 9, 2019

Re: June 9, 2019

Re: June 9, 2019