ACCEPTED SOLUTION
Accepted Solutions
One mathematics teacher (a women!) from the Air Force Academy found a mistake in my model!
See please the attach!
I dont't experience any errors when I open your 8-flyer files.
Both the Mathcad 15 and the Prime file seem to work OK and show the plots.
Can you be more specific about what is not OK and what is broken?
Here is what I see in MC15
and here is P5
Thanks Alan and Werner!
8 bats fly out of cube tops. They fly in pairs against each other 1->2, 2->6, 6->7, 7->3, 3->4, 4->8, 8->5 and 5-1 (see the picture). The model with 4 bats works without errors. In the Model with 8 bats - the wrong answer. This is my mistake or mistake Mathcad. May be Mathcad can work with 20 operators in the vector and cannon works with 40 ones!
Thanks Alan!
See animations! Is it correct - not square and the meeting not in the center of the cube?
@AlanStevens wrote:
If you start with a a more symmetrical arrangement (such as all points chasing targets on adjacent edges) you end up with a central final arrangement.
Alan
But it is possible only with 2D problem (a square) and not possible with 3D one (a cube) 
Or?
Simply exchange the start coordinates of points 5 and 8 and also of points 6 and 7 to achieve a better symmetry.
A real perfect symmetry would not be possible using all 8 vertices of the cube.
You may consider using the 6 centre points of the side surface squares of the cube (vertices of a regular octahedron).
I guess its not Mathcad but the way you had setup the problem.
There sure should no points go outside the tetrahedron.
I digged into my archive and found an old sheet were I played around with a similar "problem" and quickly adapted it to your scenarios. Here's what I see:
Thanks, Werner!
And send please the Mathcad sheet!
ps
One legendary soviet milk packing
