Mohit Muthanna wrote:
> On 8/21/05, Vance A Heron <heron / jpl.nasa.gov> wrote:
 >> [...]
>>Here's the puzzle that takes a *long* time - I don't
>>remember if it's even solvable, but my solver has
>>been running for over an hour so far ...
>>+-------+-------+-------+
>>| _ _ _ | _ _ _ | _ _ _ |
>>| 7 _ _ | _ 8 _ | 3 _ _ |
>>| _ _ _ | 7 _ _ | _ _ _ |
>>+-------+-------+-------+
>>| _ _ _ | _ _ _ | _ _ _ |
>>| _ _ 9 | _ 1 _ | _ _ _ |
>>| _ _ _ | _ _ 7 | _ _ _ |
>>+-------+-------+-------+
>>| _ _ 1 | _ _ 8 | _ 2 _ |
>>| _ _ _ | _ 2 6 | _ _ 1 |
>>| _ _ _ | 3 _ 5 | _ _ _ |
>>+-------+-------+-------+
 >
> Here's what my solver spewed out for this:
> 
> Problem:
>     1  2  3  4  5  6  7  8  9
>   +--------------------------
> 1 | _, _, _, _, _, _, _, _, _
> 2 | 7, _, _, _, 8, _, 3, _, _
> 3 | _, _, _, _, _, _, _, _, _
> 4 | _, _, 9, _, 1, _, _, _, _
> 5 | _, _, _, _, _, 7, _, _, _
> 6 | _, _, 1, _, _, 8, _, 2, _
> 7 | _, _, _, _, 2, 6, _, _, 1
> 8 | _, _, _, 3, _, 5, _, _, _
> 9 | _, _, _, _, _, _, _, _, _
> Filled: 14 / 81

This is missing the third row of the original Problem, which probably 
isn't solvable. (At least my solver claims that it isn't after  0.08 
seconds of calculation... ;)

Dennis