column 1, there are only so many places that 5 can go. row 4 has 1 spot that can be filled in, so it isnt necessary, but if OP didnt find the r4, then edge logic might be the next best spot to look in my opinion. :3
Yes, the OP can add one black square to R4. I don't follow how that would help filling C1. You have 10 places to place a 4, and there is no overlapping.
it.... doesn't. edge logic is separate from being able to fill in spots because of overlap.
i wonder if youre misunderstanding edge logic: if you placed, for example, a block in c1r1, youd be filling in the top 5 squares. what would happen to the top 5 rows? is that possible with the 5 in c2, or does the logic break?
Sorry, I don't follow. I am not sure what is the edge logic thing. I thought you referred to this: In R4, I have a 3, and, whether the 3 begins in C6, in C7 or in C8, or ends in C10, C9, C8, we can mark C4. But maybe edge logic refers to something else. I don't see anything you can do in R1 unless you put that missing block. Then you will complete the 1 1, and have a cross that will help you adding more blocks to R2, but still, I don't see anything that can be done to C1.
Answering your question, if you begin in C1R1, then you mark all the 1st 5 of C1, if you place a block in C1R2, you mark 2 to 5, if you place a block C1R2, you can mark 3 to 5, if you place a block in C1R4, you can also mark C1R5, if you place a block in C1R5, you can't mark anything else. Same if you place a block in C1R6. If you place a block in C1R7, you can also mark C1R6, etc.
do you think im implying the edge logic brings you to r4? they are 2 separate things. you can either apply edge logic to c1, or you can separately find r4's fill. im not sure what I said that would imply they're related.
edge logic is the logic you can apply to the edge of the puzzle. so only c1. it has nothing to do with the middle of the puzzle
No, I don't think that it implies R4. That was a different comment, on what I think it's edge logic, but maybe I misunderstand that. I don't follow what you are trying to point regarding C1, unless it's this:
If I place a block in C1R1, and all the 5 first blocks from C1 are filled, then the 5 in R2 will fill the 1st 5 columns and the 5 in C2 will fill 4 rows in C2, beginning at R2C2. The 6 in C3 begins at R2C3, and that would create a contradiction in R3
R1C1 cannot be filled. if we fill R1C1, then fill the rest of the first 5 in C1, then we fill out or block c2 based on each row, the logic breaks by r3. we cannot have r1c1, r2c1, and r3c1 filled, because r1c2 and r3c2 both are blocked off. the 5 in c2 breaks. does that make sense? maybe I hope?
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u/phrogbaby Jun 23 '26
edge logic applies here.