[r-t] Jump methods

[Mark Davies]

> On higher numbers, 1234567890ET to 1324675980TE would be notated 145->70
> [ie places made in lead and 4ths, 5 jumps to 7, place made in 10ths].
> And so on.

So how would you show 12345678 to 21364587? "34<-6" I suppose, but it's a
little less intuitive somehow. This system is also useless for multiple
jumps within a change.

Mathematical permutation notation could be used as a general solution, e.g.
(12)(3645). Whatever that means... I can't remember.

MBD