### ... by: Robin Thornton, France

Hi,

I have a problem concerning the Daily Killer for 23/5/2013 and I have spotted an error in your explanation for a step. However firstly I would like to complement you on your marvelous site and thank you for all the pleasure it has given me.

I was stuck in attempting to solve yesterday's Killer so I stepped through your solution and all went exactly according to my own progress until I reached the step in which you said that the 4's could be removed from A4 and A6 on the grounds that the valid combinations for a Cage of value 10 with 3 cells would not allow them. Here you gave the valid numbers adding up to 10 for a Cage of 3 cells in which you included 8 and 9 which are clearly not possible (the error). I cannot reproduce the puzzle so I can only refer to my own paper version. At this point I had possibles :-

A5 1,3,4,5

A6 1,3,4,5

B5 2,4,5,6

As there is no 1 in B5 it would be perfectly possible to have:

A5 1 A5 4

A6 4 or A6 1

B5 5 B5 5

Hence no reason to remove the 4's from A5 and A6?

As your Solver managed to solve the Killer your action must have been correct but for the life of me I cannot understand your reasoning.

Keep up the good work!

Regards,

Robin Thornton

I have a problem concerning the Daily Killer for 23/5/2013 and I have spotted an error in your explanation for a step. However firstly I would like to complement you on your marvelous site and thank you for all the pleasure it has given me.

I was stuck in attempting to solve yesterday's Killer so I stepped through your solution and all went exactly according to my own progress until I reached the step in which you said that the 4's could be removed from A4 and A6 on the grounds that the valid combinations for a Cage of value 10 with 3 cells would not allow them. Here you gave the valid numbers adding up to 10 for a Cage of 3 cells in which you included 8 and 9 which are clearly not possible (the error). I cannot reproduce the puzzle so I can only refer to my own paper version. At this point I had possibles :-

A5 1,3,4,5

A6 1,3,4,5

B5 2,4,5,6

As there is no 1 in B5 it would be perfectly possible to have:

A5 1 A5 4

A6 4 or A6 1

B5 5 B5 5

Hence no reason to remove the 4's from A5 and A6?

As your Solver managed to solve the Killer your action must have been correct but for the life of me I cannot understand your reasoning.

Keep up the good work!

Regards,

Robin Thornton

Andrew Stuart writes (25-May-2013):

Very well observed and yes there was a bug in the output string. Took me all day to track down because a) the code is a few years old now in those parts and b) we are dealing with a cage that had been split, so the original 21 clue over 5 cells wasn’t being used but the pseudo cage of 10 over 3 cells. What also throw me was the solver was splitting the cage even though there were no eliminations to be done - and then moving on to the next strategy, which is okay, since normally a split cage will make things easier. I have now added the word "split" to "cage" if it is a split cage.

I've also improved the text returned on cage combinations. I also spotted another bug where the last remaining cell in a cage wasn't being returned. A Bit of a howler that as it’s an easy thing to compute and a human would fill it doing it on pen a and pencil. But it is now showing on the solver. The check was in my offline solver which is probably why I didn't spot it before.

Solvers all say version 1.94 now, so refresh a few times if you don’t see that.

I've also improved the text returned on cage combinations. I also spotted another bug where the last remaining cell in a cage wasn't being returned. A Bit of a howler that as it’s an easy thing to compute and a human would fill it doing it on pen a and pencil. But it is now showing on the solver. The check was in my offline solver which is probably why I didn't spot it before.

Solvers all say version 1.94 now, so refresh a few times if you don’t see that.