code: def oldzetazero(
      ctx, n, url="http://www.dtc.umn.edu/~odlyzko/zeta_tables/zeros1"
  ):
      n = int(n)
      if n < 0:
          return ctx.zetazero(-n).conjugate()
      if n == 0:
          raise ValueError("n must be nonzero")
      if n > len(_zeta_zeros) and n <= 100000:
          _load_zeta_zeros(url)
      if n > len(_zeta_zeros):
          raise NotImplementedError("n too large for zetazeros")
      return ctx.mpc(0.5, ctx.findroot(ctx.siegelz, _zeta_zeros[n - 1]))
  
imports: from __future__ import print_function
  from ..libmp.backend import xrange
  from .functions import defun, defun_wrapped, defun_static
label_desc: Use image node_id 6 for calling a global function with example usage: oldzetazero(ctx, n, url) and returns: ctx, ctx