# [r-t] Plain Changes, etc

Richard Smith richard at ex-parrot.com
Mon Jun 26 09:17:06 UTC 2006

```Robin Woolley wrote:

> Recent postings remind me of the simple relationship between Original Minor
> and bobs-only peals of Plain Bob Triples.

I assume you're talking about the fact that the lead heads
and ends of an extent of Plain Bob Triples form an
upside-down extent of Original Minor on the six working
bells?  The 1325476 lead end is just a cross change on the
back six, and the the 127, 147 and 12347 plain, bob and
single lead end changes are just 16, 36 and 1236 on the back
six, respectively.  If you reverse these changes, you get
16, 14 and 1456 -- exactly what you want for the lead ends
of Original Minor.

This relationship is true at other stages too -- any extent
of Plain Bob has an upside-down extent of Original, with
(n-2)th place bobs and (n-2)(n-1)n-th place singles, as its
lead ends.  For PB5, the bobs in Original are b=12 meaning
the extent of Original is in fact the plain course of PB4.

RAS

```