[r-t] Easter challenge

[ted.steele at tesco.net]

---- Philip Earis <pje24 at cantab.net> wrote: 
> Thanks you, Mr Frye. Yes, pretty obvious when you explain it like that.
> 
> As a follow-up challenge, then, can somebody list all the treble-place
> doubles treble paths which give methods than generate a plain-course
> extent?
> 
> > There's a huge number of Doubles principles which generate a true extent
> > in the plain course. SH
> 
> Umm, yes. Well I never.
> 

I have played around with the idea of finding a rules based method (Dixonoid, I believe is the term) that gives the extent of doubles, or else (and preferably) the 60 in-course changes. Although I haven't followed it through it was beginning to look impossible. Any ideas? The nearest I got was 96 changes if I recall correctly. I suspect that a simple proof of impossibility may be available, along the lines of the one quoted above.

Ted