[r-t] Doubles 240s

[Iain Anderson]

On 2015-03-20 07:02, Richard Johnston wrote:
> Are there any historical examples of the use of the identity change?
> If there are, as is the case for jump changes, then a plausible case
> might be made for the inclusion of the identity, but not otherwise.
>
Are there any historical examples of the use of the change that swaps 
only E and T?
If not then I propose that we explicitly exclude that change too.
IJA