More Parabola stuff

Hi,
I got involved in a rather heated discussion some years back over the correct formula for a parabola, so I wrote a lisp program
Parabola.lsp to demonstrate that I was right, although knowing x^2=y may not guarantee one a place among the mental giants of our
time.
Anyway, if anyone wants a copy they can have a look at my page at http://www.cadvision.com/whites
I have also included a second routine which generates a parabola as a polyline, without the light rays reflected to the focus,
which is more practical if less beautiful, and there is a gif of the result of running the first program in case anyone just wants
to look.
The second routine (Para.lsp) generates an internal list of points which could very easily be written out to a file if one wanted
to suck them into a program which couldn't read a dxf. Similarly, if anyone needs to generate points in excel or some other program
and suck them into Acad, that is also pretty trivial - I have a number of routines to read and write data to and from external
files, generate various patterns, etc.

Thanks for an interesting group,

Simon