Update of bug #9216 (project axiom):

Status: None => transferred

Example of code trigerring the bug:

f:=operator 'f

(1)

D(sum(f(i),i=a..x),x)

   >> Error detected within library code:
   a sum cannot be differentiated with respect to a bound

is nonsense. The problem is in COMBF/dvdsum:

dvdsum(l, x) ==
  x = retract(y := third l)@SE => 0
  k := retract(d := second l)@K
  differentiate(h := third rest rest l,x) * eval(f := first l, k, h)
  - differentiate(g := third rest l, x) * eval(f, k, g)
  + opdsum [differentiate(f, x), d, y, g, h]

Although this:

is a nice try, it is wrong. It seems that the order of magnitude is roughly correct, but that's about it.

Unfortunately, I do not know how to return the thing unevaluated, so I cannot fix the bug yet

Category: => Axiom Compiler Severity: => critical Status: => duplicate