The New Sudoku Players' Forum

[denis_berthier]

My understanding is: t-candidates may be the meaning of target candidates, as the starting point in the chain. And z-candidates should be the candidates (rlc) contained in all preceding nodes of the chain.

Exactly the opposite. Is it so difficult to read a definition instead of expressing guesses?

I think whip is actually a reduced version of dynamic CRCD (cell / region / convention / double forcing chain), and dynamic CRCD is basically equivalent to braid.

Totally absurd. Once more, when you don't know what you're talking about, taking 5 minutes for reading may be a good idea.
Dynamic xxxx chains are "chains/networks of inferences". Their "size" (used in ratings) is the number of "nodes" (i.e. inferences). Totally alien to the basic idea of whips/braids...

However, the LLC formed by the RLC in braid and whip is mostly hidden.

"the LLC formed by the RLC in braid": what does this jumble of words mean?

[yzfwsf]

The chain diagram of whip7 is as follows:

whip[7]: r1n7{c2 c8} - r1n1{c8 c7} - b3n6{r1c7 r2c7} - r8c7{n6 n4} - r9c8{n4 n1} - r9c2{n1 n2} - c7n2{r9 .} ==> r1c2≠9
9r9c2 Coloring error, it should be blue.
Assuming r1c2=9, it will lead to the conclusion that there is no 2 in the seventh column, so r1c2<>9. This is the dynamic region contradiction chain.

[denis_berthier]

The chain diagram of whip7 is as follows:

whip[7]: r1n7{c2 c8} - r1n1{c8 c7} - b3n6{r1c7 r2c7} - r8c7{n6 n4} - r9c8{n4 n1} - r9c2{n1 n2} - c7n2{r9 .} ==> r1c2≠9
Assuming r1c2=9, it will lead to the conclusion that there is no 2 in the seventh column, so r1c2<>9. This is the dynamic region contradiction chain.

No, this is not at all a representation of the whip[7]; it doesn't even show a single continuous line between candidates. Once more, read the definitions before making claims about what you don't understand.

Because you can superficially translate a whip to your thing doesn't make it identical to your thing. Is this so hard to understand?
Your thing is based on basic inference steps. My whip is defined as a pure logic formula. Both are rated according to totally different principles.

You could as well argue that a whip is T&E, because this is what you are doing with your thing. And you could display the full page necessary to prove the elimination. I guess Sudoku explainer can even need 3 pages to do this.


Time to ask: has anyone ever seen anything proven about any of the "chains" "defined" in Sudoku Explainer?

[champagne]

Time to ask :

has anyone seen a default in the logic applied in Sudoku Explainer.?? (including chains and chain nets logic??)

Nicolas Juillerat made in 2004/2005 a remarkable job. Nearly 20 years later, it remains a reference on many points.
Prosecuting him is unfair.

[denis_berthier]

Time to ask :
has anyone seen a default in the logic applied in Sudoku Explainer.?? (including chains and chain nets logic??)
Nicolas Juillerat made in 2004/2005 a remarkable job. Nearly 20 years later, it remains a reference on many points.
Prosecuting him is unfair.

As usual with you, completely beside the point.
I have on many occasions said SE was a good system and I can't see any "prosecution" in what I said here.
The only "logic" in SE is that its eliminations are correct. Who ever doubted this? They are the result of various trivial forms of T&E.

My question was and remains, for serious people, has anything non trivial ever been proven about the different SE networks of inferences - I mean something as e.g. my T-braids vs T&E(T) theorems or my various confluence theorems.

You have made a copy of SE (skfr) and you don't even understand why isomorphic puzzles can have different ratings.

[champagne]

The chain diagram of whip7 is as follows:
whip[7]: r1n7{c2 c8} - r1n1{c8 c7} - b3n6{r1c7 r2c7} - r8c7{n6 n4} - r9c8{n4 n1} - r9c2{n1 n2} - c7n2{r9 .} ==> r1c2≠9

Assuming r1c2=9, it will lead to the conclusion that there is no 2 in the seventh column, so r1c2<>9. This is the dynamic region contradiction chain.

Hi yzfwsf,

are you sure to use the same PM as in the whip??

I did not learn the writing rules for the whip, but the first term seems to tell

7r1c2 false => 7 r1c8 true which is correct, we have a bi-value.
- r1n1{c8 c7} seems to tell
7 r1c8 => <1) r1c8 => 1r1c7
and here it does not work.Digit 1 is not bi value in row and not bi-value in box.


and your diagram is easy to follow


EDIT note : with a front step 9r1c2 => -7r1c2;-1r1c2 we would have a bi-value in row

[yzfwsf]

The chain diagram of whip7 is as follows:
whip[7]: r1n7{c2 c8} - r1n1{c8 c7} - b3n6{r1c7 r2c7} - r8c7{n6 n4} - r9c8{n4 n1} - r9c2{n1 n2} - c7n2{r9 .} ==> r1c2≠9

Assuming r1c2=9, it will lead to the conclusion that there is no 2 in the seventh column, so r1c2<>9. This is the dynamic region contradiction chain.

Hi yzfwsf,

are you sure to use the same PM as in the whip??

I did not learn the writing rules for the whip, but the first term seems to tell

7r1c2 false => 7 r1c8 true which is correct, we have a bi-value.
- r1n1{c8 c7} seems to tell
7 r1c8 => <1) r1c8 => 1r1c7
and here it does not work.Digit 1 is not bi value in row and not bi-value in box.


and your diagram is easy to follow

Beause r1c2=9 ==>r1c2<>1;r1c8=7==>r1c8<>1, so only r1c7 can set 1 in row 1.
It is a dynamic chain.

[champagne]

Because r1c2=9 ==>r1c2<>1;r1c8=7==>r1c8<>1, so only r1c7 can set 1 in row 1.
It is a dynamic chain.

yes I agree, this was my EDIT, but this is not in the whip written so how did it come if it is the same PM???
My attempt was to match the whip and your net

[yzfwsf]

Because r1c2=9 ==>r1c2<>1;r1c8=7==>r1c8<>1, so only r1c7 can set 1 in row 1.
It is a dynamic chain.

yes I agree, this was my EDIT, but this is not in the whip written so how did it come if it is the same PM???
My attempt was to match the whip and your net

The starting point of this whip is r1c2=9.

[champagne]

Because r1c2=9 ==>r1c2<>1;r1c8=7==>r1c8<>1, so only r1c7 can set 1 in row 1.
It is a dynamic chain.

yes I agree, this was my EDIT, but this is not in the whip written so how did it come if it is the same PM???
My attempt was to match the whip and your net

The starting point of this whip is r1c2=9.

Ok ,I worked with what I saw in your post

whip[7]: r1n7{c2 c8} - r1n1{c8 c7} - b3n6{r1c7 r2c7} - r8c7{n6 n4} - r9c8{n4 n1} - r9c2{n1 n2} - c7n2{r9 .} ==> r1c2≠9

here the start r1c2 =9 is not shown
I'll restart the match work.

[eleven]

Now i look at the link r9c8{n4 n1} - r9c2{n1 n2}. Why not 9 ?

9 where? A link is a link. There's no 9 in it.
If you mean why not 9 in r9c2{n1 n2}, it's obvious: because n9r9c2 is a z-candidate (linked to the target n9r1c2.

Ok, and r9c8{n4 n1} is a valid link, because 7 is a z-candidate (?) from the first link r1n7{c2 c8}, and c7n2{r9 .} is an impossible link, because in the 3rd link b3n6{r1c7 r2c7} 6 is a ?-candidate in r2c7. Have i got it ?

[yzfwsf]

Ok ,I worked with what I saw in your post

whip[7]: r1n7{c2 c8} - r1n1{c8 c7} - b3n6{r1c7 r2c7} - r8c7{n6 n4} - r9c8{n4 n1} - r9c2{n1 n2} - c7n2{r9 .} ==> r1c2≠9

here the start r1c2 =9 is not shown
I'll restart the match work.

In fact, what you see is the standard expression of whip, which I did not modify, and is also quoted from eleven's post.

[champagne]

Now i look at the link r9c8{n4 n1} - r9c2{n1 n2}. Why not 9 ?

9 where? A link is a link. There's no 9 in it.
If you mean why not 9 in r9c2{n1 n2}, it's obvious: because n9r9c2 is a z-candidate (linked to the target n9r1c2.

Ok, and r9c8{n4 n1} is a valid link, because 7 is a z-candidate (?) from the first link r1n7{c2 c8}, and c7n2{r9 .} is an impossible link, because in the 3rd link b3n6{r1c7 r2c7} 6 is a ?-candidate in r2c7. Have i got it ?

Hi eleven,

we have both to learn the writing rules of whips.

As you can see, I am locked at the second term of the sequence on which I am working,
Adding at the start 9r1c2 fits with my understanding of the logic

[eleven]

Back to Robert's puzzle then.
Denis, how would you make the elimination -1r13c7 in the first step ?

[champagne]

Hi yzfwsf,

matching the whip and the image

whip[7]: r1n7{c2 c8} - r1n1{c8 c7} - b3n6{r1c7 r2c7} - r8c7{n6 n4} - r9c8{n4 n1} - r9c2{n1 n2} - c7n2{r9 .} ==> r1c2≠9

Code: Select all

a) 9r1c2 => -1r1c2,-7r1c2;-9r9c2             missing 
b) 7r1c8 => -1r1c8 ;-6r1c8 ;-1r8c7;-7r9c8    r1n7{c2 c8}
c)(-1r1c2,-1r1c8) 1r1c7=>-6r1c7              r1n1{c8 c7}
d)(-6r1c8,-6r1c7) 6r2c7=>-6r8c7 ;-2r2c7      b3n6{r1c7 r2c7}
e)(-1r8c7,-6r8c7)4r8c7=>-4r9c8               r8c7{n6 n4}
f)(-4r9c8 ;-7r9c8)1r9c8=>-1r9c2              r9c8{n4 n1}
g)(-1r9c2 ;-9r9c2)2r9c2=>-2r9c7              r9c2{n1 n2}
and now the last pieces of the whip    - c7n2{r9 .} ==> r1c2≠9
Clearly we have no “2” in the column 7 

If you change the color for 9r9c2 (blue) the match is 100% correct and I can understand the whip left to right adding 9r1c2 at the start


BTW, the way I wrote it is more or less what you can find in Sudoku Explainer comments
And I have difficulties to think that the sequence can be red write to left

Edit
Sudoku Explainer does not recognize the status "empty column "7" for the digit "2".
Sudoku Explainer will produce here 2 chains showing the contradiction in the best way