I've got a puzzle here where one of the blocks looks like this:

- Code: Select all
`5 4 {7, 8}`

{3, 6, 8} 2 {6, 8}

{3, 7, 8} 1 9

Where {x, y .. } indicates that the cell must contain one of x, y, ...

(I didn't see a standard notation, so I've come up with this in the hope that it's not too confusing).

Let us refer to:

the {7, 8} choice as A

the {3, 6, 8} choice as B

the {6, 8} choice as C

the {3, 7, 8} choice as D

Now, given an analysis of (what I understand of) naked pairs, we get:

- A and D are 7 and 8

- B and C are 6 and 8

- one of B and D MUST be 3.

If the first statement holds true, then the 3 choice can be removed from B. This means that B must hold 3, which means that C holds 6, which leaves A and D. However, the same logic holds for the second statement, with A swapped for C and B swapped for D.

The question I have is - have I missed anything about this situation? Is there anything else I can work out with the information given? It feels like I should...