Function: lfuneuler
Section: l_functions
C-Name: lfuneuler
Prototype: GGp
Help: lfuneuler(L,p): return the Euler factor at p
  of the L-function given by L (Lmath, Ldata or Linit) assuming the L-function
  admits an Euler product factorization and that it can be determined.
Doc:  return the Euler factor at $p$ of the
  $L$-function given by \kbd{L} (\kbd{Lmath}, \kbd{Ldata} or \kbd{Linit}),
  assuming the $L$-function admits an Euler product factorization and that it
  can be determined.
  \bprog
  ? E=ellinit([1,3]);
  ? lfuneuler(E,7)
  %2 = 1/(7*x^2-2*x+1)
  ? L=lfunsympow(E,2);
  ? lfuneuler(L,11)
  %4 = 1/(-1331*x^3+275*x^2-25*x+1)
  @eprog
