[r-t] General case of an extent

[Philip Earis]

Joe:
"I was wondering if such a thing has ever been devised as a composition  of 
an extent which can be extended to arbitrarily many bells. Either of a 
particular method or of methods with certain lead end groups and clean 
proof"

There was some discussion about this on this list in June 2006.  It may 
interest you to take a look at the archives for that month 
(http://bellringers.net/pipermail/ringing-theory_bellringers.net/2006-June/date.html) 
 - the thread has the subject-line "Decisions / Algorithms for generating 
the extent".