dailysudoku.com

[djray]

Current puzzle from Sudoku XP5 @paulspages.com

4 . 7 . 9 2 . 6 .
. 6 2 8 5 . 7 4 .
5 . . 4 7 6 . 2 3
. . 8 . 2 4 . 5 .
2 . . 5 . 7 . . 6
. 5 . 9 . . 2 . .
8 . . . . 5 . . 2
. 2 6 . . 8 . 1 .
. 4 5 2 1 9 6 . .


Current Candidates:

Code:
+----------------------+----------------------+----------------------+
| 4 38 7 | 13 9 2 | 58 6 158 |
| 139 6 2 | 8 5 13 | 7 4 19 |
| 5 189 19 | 4 7 6 | 189 2 3 |
+----------------------+----------------------+----------------------+
| 13679 379 8 | 136 2 4 | 39 5 179 |
| 2 139 1349 | 5 38 7 | 1489 389 6 |
| 1367 5 34 | 9 368 13 | 2 378 478 |
+----------------------+----------------------+----------------------+
| 8 1379 139 | 367 346 5 | 349 379 2 |
| 379 2 6 | 37 34 8 | 3459 1 4579 |
| 37 4 5 | 2 1 9 | 6 378 78 |
+----------------------+----------------------+----------------------+


Hint: The blue and green squares form a Type 3 Discontinuous Nice Loop ([R4C2] -3- [R1C2] =3= [R2C1] -3- [R9C1] -7- [R7C2] =7= [R4C2]). The discontinuity is at the blue square. Candidate 3 can be eliminated from this square.

My 1st of many questions is the notation ([R4C2] -3- [R1C2] means a weak link between ([R4C2] & [R1C2] which are candidates [379] vs [38] is this true?

2nd-Is this a weak link because these two cells ([R4C2] & [R1C2] share only one candidate=3 ??

3rd-Isn't there also a link between ([R4C2] & [R7C2] which are candidates [139] vs [1379] ?

I understand xy chains,forcing chains and forcing loops since these only include bivalue cells. However I am totally confused when cells with 3 or more candidates are in the equation.

Can someone explain the notation as to why there are weak links and strong links.([R4C2] -3- [R1C2] =3= [R2C1] -3- [R9C1] -7- [R7C2] =7= [R4C2]). The discontinuity is at the blue square. Candidate 3 can be eliminated from this square.

Your help will be greatly appreciated. I thank you

[Marty R.]

Any reason for starting another thread with the same post?