Dear Professor David or Jo Anne Ryeburn,

Finally,
I accomplished the study
of this most interesting article...

But, with your permission,
I can not resist to notice that
the key-point of the surprising,
at least to me, introduction
of an ellipse at step (3),
it looks somehow artificial
and in some way opposite
to the intentions of the introduction:

| ...
| don't believe in using calculus
| whenever simple geometry and/or algebra
| makes it unnecessary.
| A proof that avoids calculus can be meaningful for
| those who don't know calculus,
| or who haven't used it for a while
| ...

In all other respects
and as far as I could say something more,
then it is, at least for me,
a perfect argument, indeed!

Sincerely yours,

pez
SV7BAX
TheDAG