Function: sumdivmult
Section: sums
C-Name: sumdivmultexpr0
Prototype: GVE
Wrapper: (,,G)
Description:
  (gen,,gen):gen sumdivmultexpr(${3 cookie}, ${3 wrapper}, $1)
Help: sumdivmult(n,d,expr): sum of multiplicative function expr,
 d running over the divisors of n.
Doc: sum of \emph{multiplicative} expression \var{expr} over the positive
 divisors $d$ of $n$. Assume that \var{expr} evaluates to $f(d)$
 where $f$ is multiplicative: $f(1) = 1$ and $f(ab) = f(a)f(b)$ for coprime
 $a$ and $b$.
 \synt{sumdivmultexpr}{void *E, GEN (*eval)(void*,GEN), GEN d}
