[r-t] Converting Plain Bob Triples to St. Simon's and vice versa

[Matthew Frye]

On 16 Jun 2012, at 12:50, Robert Bennett wrote:
> 
> Bob Course of St Simon's Triples: 
> 
> Â 234567 
> 
> -642375 
> 
> -726453 
> 
> -567234 
> 
> -375642 
> 
> -453726 
> 
> -234567 
> 
> The bob course of Plain Bob Triples has 4 leads. You can convert the
> above to a much longer touch of PB Triples by ringing the exact same
> bobbed leads, but touches so converted are not necessarily true. 

There are subtleties here, and interesting ones I think. My mind leapt straight to the bob course as a counter-example, but it doesn't really cut it very well. There is no falseness introduced and no immediate implication I can see that it inevitably leads to falseness (the selection of q-sets still partitions the extent into a series of mutually true round block).

Consider instead the plain bob touch: FIO OFI IOF. Nice and simple (from the 2 it's MMM HHH WWW). Obviously valid.
According to Eddie's simple conversion scheme what we get in St Simon's: FIO OFI IOF is actually the same due to it being palindromic (incidental here, I think) however we clearly have a problem right after the first Out, in that we're back in the plain course and the next call isn't appearing before the course end, so it comes round/runs very false depending how you want to look at it.

Rather than leave it there, we can attempt to fix this, perhaps suggesting the following: IOF OFI FIO which works and looks very much like the original pb touch.

I have more thoughts on this, but feel my thoughts might be aided by some thinking over some lunch, so shall leave it there for now.

MF