On Tue, 14 Jan 2014 22:03:14 +0000, And Rosta <[log in to unmask]> wrote:

>Is this for the simple system for unsavvy person X to use to enable
>locked-in person Y to communicate with X? If that is devised and
>promulgated, it will be a real service to the world.

It's not for that, but that is slowly moving forward as well.  Here are the current notes:

Some supplementary material is at
including programs for producing the binary and ternary trees given a frequency distribution, whence the figures of 4.3 and 3.3 questions per letter cited there.  (Though the figures will be lower if one takes advantage of context.)