The New Sudoku Players' Forum

[zr1skydiver]

I was looking at a solution for a sudoku puzzle that was provided to me on the internet.

One line had the following:

"removing 3 from [A5] using chain rule (method D)"

Anyone know what the chain rule is and where I could find a detailed description of what it is?

[Mike Barker]

I googled "Chain rule method D Sudoku". This is not standard terminology, but one possibility is that it is just a naked set (pair, triple, etc). The reference is:

http://www.sudokusolver.co.uk/solvemethods.html

If you still have a question, feel free to post the puzzle.

[Ruud]

When you run the example in the online solver it gives these hints for naked subsets:

.. removing 7 from [D3] using chain rule (method D)

See also: Number chain definition in Gaby's dictionary.

Ruud