code: def hermemul(c1, c2):
      """
      Multiply one Hermite series by another.
  
      Returns the product of two Hermite series `c1` * `c2`.  The arguments
      are sequences of coefficients, from lowest order "term" to highest,
      e.g., [1,2,3] represents the series ``P_0 + 2*P_1 + 3*P_2``.
  
      Parameters
      ----------
      c1, c2 : array_like
          1-D arrays of Hermite series coefficients ordered from low to
          high.
  
      Returns
      -------
      out : ndarray
          Of Hermite series coefficients representing their product.
  
      See Also
      --------
      hermeadd, hermesub, hermemulx, hermediv, hermepow
  
      Notes
      -----
      In general, the (polynomial) product of two C-series results in terms
      that are not in the Hermite polynomial basis set.  Thus, to express
      the product as a Hermite series, it is necessary to "reproject" the
      product onto said basis set, which may produce "unintuitive" (but
      correct) results; see Examples section below.
  
      Examples
      --------
      >>> from numpy.polynomial.hermite_e import hermemul
      >>> hermemul([1, 2, 3], [0, 1, 2])
      array([ 14.,  15.,  28.,   7.,   6.])
  
      """
      # s1, s2 are trimmed copies
      [c1, c2] = pu.as_series([c1, c2])
  
      if len(c1) > len(c2):
          c = c2
          xs = c1
      else:
          c = c1
          xs = c2
  
      if len(c) == 1:
          c0 = c[0] * xs
          c1 = 0
      elif len(c) == 2:
          c0 = c[0] * xs
          c1 = c[1] * xs
      else:
          nd = len(c)
          c0 = c[-2] * xs
          c1 = c[-1] * xs
          for i in range(3, len(c) + 1):
              tmp = c0
              nd = nd - 1
              c0 = hermesub(c[-i] * xs, c1 * (nd - 1))
              c1 = hermeadd(tmp, hermemulx(c1))
      return hermeadd(c0, hermemulx(c1))
  
imports: from __future__ import division, absolute_import, print_function
  import warnings
  import numpy
  import numpy.linalg
  from numpy.core.multiarray import normalize_axis_index
  from .None import polyutils
  from ._polybase import ABCPolyBase
label_desc: Use image node_id 8 for calling a global function with example usage: hermemul(c1, c2) and returns: hermeadd