Home   Join   Puzzles   Solvers   Forums   Archives   Competitions   Techniques  
    News   Contact   Puzzle Packs   Publication   Crosswords   Codewords   Schools
SolvingTechniques
 
Jelly Fish
 
     
 
Jelly Fish

For a real hair-pulling screamer that’s still logical, not a lot beats a Jelly-Fish – except the fabled Squirm-Bag which uses five rows and columns.  Jelly-Fish is the fourfold extension of X-Wing and Sword-Fish. 

In this example number 4 is being Jelly-Fished!

Naked Pairs
Fig. 14.1

As you can see, of the 16 nodes involved, only 11 actually contain a 4.

 

Generalizing X-Wing

X-Wing is not restricted to rows and columns. We can also extend the idea to boxes as well. If we generalise the rule in chapter 14 above we get:

When there are

  • only 2 candidates for a value, in each of 2 different units of the same kind,
  • and these candidates lie also on 2 other units of the same kind,

then all other candidates for that value can be eliminated from the latter two units.

Now we have 6 combinations: Starting from 2 rows and eliminating in 2 columns

  • Starting from 2 columns and eliminating in 2 rows
  • Starting from 2 boxes and eliminating in 2 rows
  • Starting from 2 boxes and eliminating in 2 columns
  • Starting from 2 rows and eliminating in 2 boxes
  • Starting from 2 columns and eliminating in 2 boxes

 

Classic X-Wing
Classic X-Wing
Same effect as line/box reduction
Same effect as line/box reduction
Same effect as pointing pairs

Same effect as pointing pairs
SolvingTechniques

Website Design by Splash Software Ltd Copyright 2009