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keith

Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA

Posted: Tue Feb 12, 2008 7:28 am Post subject: No insects, please!

Fun to solve:

Code:

Puzzle: M3979461sh(11)
+-------+-------+-------+
| . . 8 | . 7 . | 1 . . |
| 7 . . | . . . | . . 3 |
| . 6 2 | . . . | 7 4 . |
+-------+-------+-------+
| 1 2 5 | 6 . 8 | . . . |
| . 4 . | . . . | . 8 . |
| . . . | 4 . 7 | 2 5 1 |
+-------+-------+-------+
| . 7 6 | . . . | 5 1 . |
| 5 . . | . . . | . . 4 |
| . . 4 | . 2 . | 9 . . |
+-------+-------+-------+

Keith

Johan

Joined: 25 Jun 2007
Posts: 206
Location: Bornem Belgium

Posted: Tue Feb 12, 2008 9:02 am Post subject:

Ignoring the insect, there is an ER in Box 4 that completes the puzzle.

storm_norm

Joined: 18 Oct 2007
Posts: 1741

Posted: Tue Feb 12, 2008 4:02 pm Post subject:

Code:

|---c1--|---c2--|---c3--||---c4--|---c5--|---c6--||---c7--|---c8--|---c9--
-----------------------------------------------------------------------------
r1 | 4 | 39 | 8 || 39 | 7 | 5 || 1 | 6 | 2
---+-------+-------+-------||-------+-------+-------||-------+-------+-------
r2 | 7 | 5 | 1 || 2 | 6 | 4 || 8 | 9 | 3
---+-------+-------+-------||-------+-------+-------||-------+-------+-------
r3 | 39 | 6 | 2 || 8 | 1 | 39 || 7 | 4 | 5
===========================||=======================||=======================
r4 | 1 | 2 | 5 || 6 | 39 | 8 || 4 | 37 | 79
---+-------+-------+-------||-------+-------+-------||-------+-------+-------
r5 | r39 | 4 | 7 || 1 | 5 | 2 || g36 | 8 | 69
---+-------+-------+-------||-------+-------+-------||-------+-------+-------
r6 | 6 | 8 | g39 || 4 | 39 | 7 || 2 | 5 | 1
===========================||=======================||=======================
r7 | 2 | 7 | 6 || 39 | 4 | 39 || 5 | 1 | 8
---+-------+-------+-------||-------+-------+-------||-------+-------+-------
r8 | 5 | 139 | r39 || 7 | 8 | 16 || r36 | 2 | 4
---+-------+-------+-------||-------+-------+-------||-------+-------+-------
r9 | 8 | 1r3| 4 || 5 | 2 | 16 || 9 | g37 | 67
.............................................................................

the bug is in r8c2

ignoring it, you get a color wrap on 3

the 3 in r8c3 is red as well as the 3 in r9c2

Marty R.

Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA

Posted: Tue Feb 12, 2008 5:24 pm Post subject:

One W-Wing on one of the many pairs of 39s did it for me.

keith

Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA

Posted: Wed Feb 13, 2008 12:13 am Post subject:

My solution was the same as Norm's. Amazing, so many <39> pairs and no remote pair or deadly pattern (that I could see). Keith

Asellus

Joined: 05 Jun 2007
Posts: 865
Location: Sonoma County, CA, USA

Posted: Wed Feb 13, 2008 11:13 pm Post subject:

Johan wrote:

[T]here is an ER in Box 4 that completes the puzzle.

I've been on the lookout lately for an ER elimination that cannot also be seen as something else. I'm not sure that such an example exists. In this case, I assume that that b4 ER involves <3>s and c7 with the elimination in r8c3. If so, this can also be seen as a Sashimi Swordfish in r469.

Does anyone have an ER example that can't be seen as something else (apart from coloring, since any ER can be seen as coloring of one sort or another)?

storm_norm

Joined: 18 Oct 2007
Posts: 1741

Posted: Thu Feb 14, 2008 5:37 am Post subject:

Asellus wrote:

Johan wrote:

[T]here is an ER in Box 4 that completes the puzzle.

I think you are right, I am not sure an example exists.

however, there are some examples of ER eliminations that go beyond what a single other technique can do.

in fact, some ERs can eliminate candidates that the combinations of finned x-wings and some other coloring would have to be used.

I see where you are going tho. the ER isn't as special as it might sound because it doesn't make eliminations that are unique in of itself.

but doesn't that apply to other techniques as well?? Smile

Asellus

Joined: 05 Jun 2007
Posts: 865
Location: Sonoma County, CA, USA

Posted: Thu Feb 14, 2008 7:40 am Post subject:

storm_norm wrote:

there are some examples of ER eliminations that go beyond what a single other technique can do.

Can you provide an example? I haven't had this particular quirky interest for long. But so far, I have been able to find a single alternate technique when I've looked hard enough. (Sashimi Jellyfish aren't always so easy to spot!)

storm_norm wrote:

I see where you are going tho. the ER isn't as special as it might sound because it doesn't make eliminations that are unique in of itself.

I'm not really saying anything about "specialness." (I'm not even sure what it is.) ERs are easy to spot, which makes them handy and useful. And, they are interesting in how they work. I just find it interesting that there may always be an alternate way to picture the same elimination that is accomplished by an ER. I'm simply wondering if that is true: if, in fact, there may be some necessary connection between the existence of an ER elimination and the existence of an alternate way of seeing that elimination. Perhaps someone else has already gone over this ground and proved or disproved it. In fact, I'd be surprised if someone hasn't,

Quote:

but doesn't that apply to other techniques as well??

I don't think so. X-Wing or XY-Wing eliminations, for example, usually seem to be uniquely the result of those concepts. Admittedly, having two or more ways to do the same elimination isn't that unusual. But, there seems to be something about ERs: they may be a sort of "short circuit" of other inherent relationships... or something like that. That's more "where I'm going."

ravel

Joined: 21 Apr 2006
Posts: 536

Posted: Thu Feb 14, 2008 9:51 am Post subject:

Asellus,

maybe this one is interesting for you. Its a sample puzzle for ER by Mike Barker.

Code:

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

storm_norm

Joined: 18 Oct 2007
Posts: 1741

Posted: Thu Feb 14, 2008 10:15 am Post subject:

ravel, that's it. that is a good example.

storm_norm

Joined: 18 Oct 2007
Posts: 1741

Posted: Thu Feb 14, 2008 10:32 am Post subject:

Code:

|---c1--|---c2--|---c3--||---c4--|---c5--|---c6--||---c7--|---c8--|---c9--
-----------------------------------------------------------------------------
r1 | 359 | 7 | 1235 || 2469 | 149 | 12469 || 235 | 8 | 2346
---+-------+-------+-------||-------+-------+-------||-------+-------+-------
r2 | 589 | 4 | 125 || 3 | 189 | 1269 || 7 | 15 | 26
---+-------+-------+-------||-------+-------+-------||-------+-------+-------
r3 | 38 | 128 | 6 || 248 | 7 | 5 || 23 | 134 | 9
===========================||=======================||=======================
r4 | 7 | 125 | 12345 || 248 | 3458 | 24 || 6 | 9 | 2348
---+-------+-------+-------||-------+-------+-------||-------+-------+-------
r5 | 345 | 25 | 8 || 2469 | 3459 | 2469 || 1 | 7 | 234
---+-------+-------+-------||-------+-------+-------||-------+-------+-------
r6 | 6 | 9 | 234 || 1 | 348 | 7 || 238 | 34 | 5
===========================||=======================||=======================
r7 | 458 | 58 | 45 || 7 | 6 | 3 || 9 | 2 | 1
---+-------+-------+-------||-------+-------+-------||-------+-------+-------
r8 | 2 | 6 | 7 || 49 | 149 | 149 || 358 | 35 | 38
---+-------+-------+-------||-------+-------+-------||-------+-------+-------
r9 | 1 | 3 | 9 || 5 | 2 | 8 || 4 | 6 | 7
.............................................................................

ignore the ER on this puzzle?
nah, forget about it.

storm_norm

Joined: 18 Oct 2007
Posts: 1741

Posted: Thu Feb 14, 2008 10:46 am Post subject:

Quote:

ERs: they may be a sort of "short circuit" of other inherent relationships... or something like that. That's more "where I'm going."

yes, I follow you on this point. I think you are on to something here.

Total coincidence that ER also stands for Electromagnetic Radiation? We know its there. We can use it. we can see it, feel it, hear it react with things. But do we fully realize what its all about? is it part of something bigger on a level we can't experience yet.

definitely worth looking into because if it is a shortcut for a larger chain and no one has identified what that relationship is then BINGO !! discoverama time. just be sure to give it a good name Laughing

Asellus

Joined: 05 Jun 2007
Posts: 865
Location: Sonoma County, CA, USA

Posted: Thu Feb 14, 2008 10:04 pm Post subject:

ravel, Thanks for the response. As far as I can see, that puzzle contains only a single ER: on <2> in b1 with r6. It can also be seen as a Kite pivoting in b4. Thus, it doesn't provide what I am looking for. (It also solves the puzzle, so there are no other ER encounters.)

keith

Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA

Posted: Thu Feb 14, 2008 11:44 pm Post subject:

Asellus wrote:

Thus, it doesn't provide what I am looking for.

Asellus,

Maybe if you make diagrams of all possible ER's that you are looking for, you can begin to understand why some might not be found, or are found under other names.

I am still looking for a useful Type 5 Unique Rectangle.

Code:

+--------------+
| x - - |
| 46 - 246 |
| x - - |
+--------------+
| 246 - 46 |
| - - x |
| - - x |
+--------------+

In this example, "x" cannot be <2>. I have seen this pattern once or twice, but never when it made any eliminations (in the cells marked "x").

Keith

Asellus

Joined: 05 Jun 2007
Posts: 865
Location: Sonoma County, CA, USA

Posted: Fri Feb 15, 2008 4:07 am Post subject:

Keith wrote:

Maybe if you make diagrams of all possible ER's that you are looking for, you can begin to understand why some might not be found, or are found under other names.

I'm not sure how one would go about such a thing in this case. But, I'll let the idea steep.

Meanwhile, today's DM had an ER elimination that, at first glance, looked as if it might not be obtained in some other way. After staring at it carefully for a while, I noticed that there was a Jellyfish that made the same elimination (and a few others).

That's interesting about the Type 5 UR. I'll try to keep my eyes open for one. I assumed, since it had been described, that examples had actually been encountered.

ravel

Joined: 21 Apr 2006
Posts: 536

Posted: Fri Feb 15, 2008 9:54 am Post subject:

Asellus wrote:

It can also be seen as a Kite pivoting in b4.

Ah yes, i had missed that, because i only looked for big fish. This will be always there, if in the 3rd box - in the band/stack with the ER and the second strong link number - the number already is resolved.

keith wrote:

I am still looking for a useful Type 5 Unique Rectangle.

This must be extremely rare. Never saw such a grid.

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