[computer-go] Problems in SGF format

[Mark Boon]

I have a relatively small set with tactical problems that I use for  
unit-tests. When making the Tsume-Go program we used to have a very  
large set of problems we used for regression testing, for which we  
used a custom format.

Instead of hard-coding each problem as a unit-test, what I do now, I  
think it would be much handier if I could put them in a SGF file. So  
my question is if there's a standard way defined to represent such  
problems. What I'm looking for is a standard way to express "Black to  
play and catch the stone(s) at X,Y." Or "Black to play and escape  
(live) with stones X,Y".

Those are probably the only two types of problems I need. But what  
also needs to be expressed in the SGF file is the result of the  
problem so that it can be compared with the result of the  search.  
This could look like something like "Black is alive (or escaped) when  
playing X,Y". From the Tsume-Go program I learnt that ko-type  
situations can best be described by a number of passes. For example  
"Black is alive (or escaped) when playing X,Y, White passed twice."  
would mean Black is alive in a two-step ko. The more passes, the  
worse the result. The only exceptions to those were "alive in seki"  
and "dead in bent-four" as special cases. Seki is considered to be  
slightly worse than simply alive, whereas "dead in bent-four" is  
slightly worse than "dead", although it's a minor thing that I  
wouldn't mind lumping together with "alive" and "dead".

Mark