They can see cells with three, but we’ll attempt to create a chain that removes one. However, they each have the number one and can see the number one in another cell (the purple arrows point to it.) The light green squares represent the pincers in the preceding example. To accomplish so, though, you must first build a chain between the two pincers. If both pincers can view cells with the common number, you may be able to delete the shared number from those cells. In the example below, our pincers are bright green, and they both have the same candidates. Look for two bi-value cells (we’ll call them “pincers”) that can’t see each other but have at least one number in common (we’ll name it the “shared number”) to employ XY-Chain. Candidate 4 in E9 may be removed since it sees both Cells. So the answer must be in one of these Cells. In the example, depending on which way the chain is read, candidate 4 is the termination point of a Strong Link in either E1 or A9. Indeed, irrespective of how the chain is read, such a Cell “sees” a candidate that is the start of a Strong Link and a candidate that is the end of another Strong Link.īecause the candidate at the end of a Strong Link has to be the answer for that cell, it cannot be the solution for any other cell that “sees” it. If we can establish a chain that is not a loop and that begins and ends on the same contender, then any Cell that “observes” (a Cell “observes” a different Cell if both Cells relate directly to the same region) both ends of the chain cannot have that candidate as its response. The chain always begins with a Strong Link, and it always ends with a Strong Link. In the XY-CHAIN technique, we establish strong links inside “Bi-Value” Cells and Weak Links between these “Bi-Value” Cells. The following example displays an XY chain that results in elimination. The only limitation (besides the obvious needs for the links) is that the XY-Chain begins and finishes with a strong connection on the same number.Īs with X-Chains, this establishes that one of the endpoints must have that candidate put, and it may be excluded from all cells that view both ends of the chain.īecause the chain is exclusively composed of bivalue cells, the connection between the two candidates in each cell results in strong inference, allowing us to employ weak inference between the cells.Īn XY-Wing with just three cells has the shortest XY-Chain.Īn XY-Chain is a Double Implication Chain and an Alternating Inference Chain. ©Brained Up Ltd/Gareth Moore 2005-2022 - email - publishers please visit Any Puzzle Media - our privacy policy - registered in England & Wales no.The XY-Chain approach enables you to remove candidates similar to Y-Wing.Īn XY-Chain is a chain of cells that each contain just 2 candidates.Īn XY-Chain employs just bivalve cells (similar to Remote Pairs), but the cells might contain arbitrary candidates. Or are you looking for a puzzle supplier? If so then visit Any Puzzle Media Ltd. Looking for printed puzzles? Visit for puzzle books and magazines. With puzzle mix you can play Sudoku online, play Futoshiki online, play Hanjie online, play Kakuro online, play Hanjie online, play Calcudoku online, play Slitherlink online, play Killer Sudoku online - and many more! Get help from solving assistants, and make pencilmarks to help you solve. Use advanced features like undo, zoom and save. Compare your solving times with other players, and join the community to rate puzzles.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |