Normally recursive function can be evaluate symbolically without problems, like
But it looks that the symbolics has troubles with the sum - I get the "generic" variable-undefined error at first hand and when I trace, Mathcad moans that "This function refers to itself inconsistently".
As far as I remember this effect was discussed here quite a while ago in the good old collab days, but I was unable to find that thread.
Is there any explanation for this effect and does an elegant workaround exist?
The only workaround I could find was to replace the sum by a self written summation loop, which I don't consider elegant.
Writing a user function sum() in som way could be an option, but would slow down calculations which, when evaluated symbolically, take very long anyway.
Regards
Werner