[r-t] Exhausted search spaces

[Richard Smith]

David Sullivan wrote:

> RAS:
>> But I cannot believe that this was done "many years ago" and
>> the suggestion that the results were printed out is clearly
>> wrong. 
>
> Yes. This was over thirty years ago and my memory of the 
> exact wording is obviously hazy.

Maybe he was looking for a perfect three-part?  Modulo 
rotations, there are 4 such extents of Cambridge Minor and 
1770 of Plain Bob Minor.

> ISTR him saying that the first extent that was produced started with
> 5 homes, the program presumably being written to favour plain leads
> over calls. He was rather pleased to announce that the real basic
> extent of PB6 was this one, starting with 5 homes followed by a
> nightmarish mishmash of pseudo-random plains, bobs and singles.

That sounds very plausible.  My search program does 
precisely the same.  The first extent of PB6 it finds is:

....b....b....s....b....b...b....b..s...ss....s..s....sss.bs

(where a . is a plain lead).

RAS