[r-t] Find an extent using only the place notations 1,7,345

[Alexander E Holroyd]

Not so clear.  The calls you mention don't change the parity of the 
number of blocks, so how could they join an even number of blocks into one?

On 16-Jul-20 6:35 AM, Robert Bennett wrote:
> A method with a plain hunting treble:
> 345.1.7.1.7.1.7.1.7.1.345.1.
> This has 3 leads to its plain course, and is symmetrical (like a bob 
> course of grandsire triples).
> If the second 345 is changed to a 7, a usable call is produced, 
> affecting 2 x 3 bells.
> These would join 6 courses together.
> The extent is 360 leads, or 120 of the 3 lead courses, or 20 of the 6 
> course blocks.
> In principle, the 20 blocks could be joined together, either using an 
> extra 345 to replace a1, or changing a 345 to a 7.
> 
> Robert Bennett