View previous topic :: View next topic 
Author 
Message 
Robert Ferre
Joined: 09 Apr 2006 Posts: 10

Posted: Wed May 03, 2006 2:51 pm Post subject: Help from George and Keith 


George, I would he interested in your notation system.
.
Keith, I don't understand unique rectangles. I see the ones that you pointed out, although the cells have other values, too, and similar values nearby. So, I don't understand the logic that leads to the exclusions that you included with each example. I have learned that Xboxes and Swordfish have direction. Is the same true for unique rectangles? 

Back to top 


Marty R.
Joined: 12 Feb 2006 Posts: 5327 Location: Rochester, NY, USA

Posted: Wed May 03, 2006 3:50 pm Post subject: 


Keith, I just asked a similar question in the May 2 thread. 

Back to top 


keith
Joined: 19 Sep 2005 Posts: 3194 Location: near Detroit, Michigan, USA

Posted: Wed May 03, 2006 10:30 pm Post subject: Tutorial to come 


Robert and Marty,
Give me a day or two, I will post an introduction to unique rectangles.
Marty,
I was thinking of you the other day. I drove from Detroit to Ithaca, NY, passing close to Rochester. (And with Al Franken on XM radio, broadcasting that day from Rochester!)
Best wishes,
Keith 

Back to top 


George Woods
Joined: 28 Mar 2006 Posts: 259 Location: Dorset UK

Posted: Wed May 03, 2006 10:36 pm Post subject: 


I label the boxes alphabetically so Box 1 is a and box 9 is i
i.e.
a b c
d e f
g h i
so if the first move is in box e and is the insetion of a 9 I write it down as e9. If I need to refer explicitly to a cell I write it  example Fa i.e. the first cell in box F
Generallysomething like c9 is adequate, and it is hopefully ovious where to put the 9 and why! Otherwise I use additional symbols e.g. underline means "this is the only number that can go in this cell"  i.e see that all other numbers 1 to 9 can be "seen" from this cell. A bar above I use to show that it is deduced by looking along the row, and two bars the column. I use an exclamation mark to show a deduction based on an implied arrangement (e.g.that number must lie in 2 or 3 cells  allowing a deduction elesewhere). No symbol generally means obvious and at the start of a puzzle is usually"only cell that can hold this number", but near the end of a puzzle is likely to be "the only number that is allowed in this cell". I try to use commas to indicate a change of idea, so e673 means 6 then 7 and 3 are entered into e in that order, but done as a "triple" e6,7 implies the 6 and 7 derived from different threads of argument.
I sometimes write f(67) or f66 impling that I have written 67 into two cells, or e66 that 6 lies in only two of the cells, and I write very small 6 in each to remind me.
Clearly you can expand this nomenclature. What I have found is that when a puzzle "explodes", I can backtrack, and usually the mistake turns out to be only one or two moves ago!
I find the alphabetic description easier to use and is more compact e.g Fe is more compact than r5c8 

Back to top 


Robert Ferre
Joined: 09 Apr 2006 Posts: 10

Posted: Thu May 04, 2006 2:29 am Post subject: 


That was helpful, George. Thanks. It is based not only on numerical possibilities, it also indicates some of the logic involved. I think I can use a little more work on my logic, and my "seeing." I'm working on it.
Robert 

Back to top 


George Woods
Joined: 28 Mar 2006 Posts: 259 Location: Dorset UK

Posted: Thu May 04, 2006 1:42 pm Post subject: 


For what it is worth here is an example of my solution to today's puzzle (may4)
a1,e1,h1.i1,b7,e4,col2(28)d5,f7,d7,i7,g7c7a7,a5g6,h6,h9,c2,g3,d8g2,d62,a48,c4b4c5,h52,c2,e89,b3,9,c3,e63,f62,c296,i8,g458,f89,i9,i9534,a69
I have used  and  instead of bars over to indicate look in rowand look in column
The col2(2 is put in because it is a key move i.e. scan col2 for 2and 8 and you will find a "hidden pair" 

Back to top 




You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum

Powered by phpBB © 2001, 2005 phpBB Group
