Sudoku Players' Forum (clone)

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RyanStorm wrote:Wait a sec, everything is already erased in the row and house....meaning I want to remove the 1 and 9 from the first box, the 9 from the middle one, and the 3 from the far right one.
I am 99% convinced I can.

Yes, you can. And it doesn't depend on the cells being in the same row.
If "there is no 2, 6 or 8's in the house" (block), you have a Hidden Triplet in this block. You can erase any other number from the 3 cells.
Proof: as the 3 numbers must be somewhere in the block, in different cells, and there are only 3 places for them, they must occupy those 3 cells, which leaves no place for any other number in them.

On the other hand, if 2, 6, or 8 appears in any other cell in the same house/block, then you can't do anything.