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

Matthew Frye matthew at frye.org.uk
Sat Jun 16 16:26:26 UTC 2012

```On 16 Jun 2012, at 13:22, Matthew Frye wrote:
> I have more thoughts on this...

Further thoughts from a q-set point of view: Obviously we have the same set of q-sets for both methods, so everything is perfectly well defined. The only real question is if the set of q-sets joins everything up into a single cycle or not.

(side note: if a set of q-sets results in a single cycle is a rather general and important question, I'm not aware of any good general way of answering it other than trying. Any comments?)

Now, the reason Eddie's method fails for my "FIO OFI IOF" touch of pb is that there are three q-sets with members in the plain course, at F, O & I, and the first of these to be arrived at isn't the F, it's the In. If a (plain) course doesn't contain a q-set with a F/O/I or contains only 1 of them, Eddie's method *does* always reach the calling positions in the right order, works perfectly and produces a correct "reversal" in the alternate method. The St. Simon's compositions based on bob courses, mentioned by Robert, will clearly have two or more bobs F/O/I per course, so Eddie's method fails.

The interesting question now is really when a set of q-sets can still generate a true touch or, more interestingly, and extent even when Eddie's method fails, as in my example where we rearranged FIO OFI IOF to IOF OFI FIO, taking the q-sets in the correct order they're reached. This is clearly a fully acceptable move if the q-set you move involves leaving the course at one point and returning to the same point, having rung a number of complete courses (in a way that's easy to "reverse" to the new method).

Any more complex callings may have odd things go wrong in them. For example if one (plain) course has three q-sets in, say at W, M & H, if you arrive via the H, in the pb calling you leave via the W, in the St Simon's you then leave via the M into a bit of the composition you weren't expecting to be in. Sometimes this is fine (essentially as described in the previous paragraph, or if you get lucky) but you could easily split a composition into two or more separate round blocks when two of these courses that rearrange whole chunks of composition interact with each other.

I'm pretty sure I've not explained that as well as I could have, but I'm not sure if I understand it properly myself, so feel free to question, correct or tell me I'm talking nonsense.

MF

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