fsolve() crash with given Interval

[Angus]

It's interessting to see that eq[1] is translated to at(eq,0)... I do prefer zero based indices. Most people from the c/c++ world will do.
Interessting both ways seem to be mixed up in the prime? That could be fixed aswell (just to point to some inconsistancies, again)

edit: CR Haeger's question is something I do, too have not understood. What workflow on things like this did you guys at HP have had in mind in the design stage of development? I think the fixed named variables trick me...