On Wed, 11 Jul 2007 13:30:55 -0700, JL wrote:

There's a rule which says that you cannot pass any station (where the
train stops) which buying a ticket to would cost more than buying a
ticket to the destination station.

No, there is not.

The doubling back is a deviation of
this rule.

Doubling-back is nothing to do with the above.

The rules are a lot more complicated than you are trying to make out.
Have a read of the online Routeing Guide and it will make sense.
There is a fares rule, and there is a doubling-back rule, but neither
are as you state.

Neil

--
Neil Williams
Put my first name before the at to reply.