The XY-Chain technique is the combination of 3D Medusa and X-Chain, meaning we

  • look for alternating weak and strong links, and
  • consider links between identical candidates within a region, as well as
  • different cell candidates within a single cell.

If you have not read about 3D Medusa and X-Chain, do it now. XY-Chain brings nothing new to the table.

Both, XY-Chain and AIC are simply 3D Medusa and X-Chain put together. XY-Chains have one restriction, though, compared to AICs:

With XY-Chain, only strong links will be considered between different cell candidates within a single cell. That way they are a bit easier to find than AICs, but still extremely difficult.

XY-Chain Examples

possible solution group
possible solution group
the candidates we can eliminate