code: def chebsub(c1, c2):
      """
      Subtract one Chebyshev series from another.
  
      Returns the difference of two Chebyshev series `c1` - `c2`.  The
      sequences of coefficients are from lowest order term to highest, i.e.,
      [1,2,3] represents the series ``T_0 + 2*T_1 + 3*T_2``.
  
      Parameters
      ----------
      c1, c2 : array_like
          1-D arrays of Chebyshev series coefficients ordered from low to
          high.
  
      Returns
      -------
      out : ndarray
          Of Chebyshev series coefficients representing their difference.
  
      See Also
      --------
      chebadd, chebmulx, chebmul, chebdiv, chebpow
  
      Notes
      -----
      Unlike multiplication, division, etc., the difference of two Chebyshev
      series is a Chebyshev series (without having to "reproject" the result
      onto the basis set) so subtraction, just like that of "standard"
      polynomials, is simply "component-wise."
  
      Examples
      --------
      >>> from numpy.polynomial import chebyshev as C
      >>> c1 = (1,2,3)
      >>> c2 = (3,2,1)
      >>> C.chebsub(c1,c2)
      array([-2.,  0.,  2.])
      >>> C.chebsub(c2,c1) # -C.chebsub(c1,c2)
      array([ 2.,  0., -2.])
  
      """
      return pu._sub(c1, c2)
  
imports: import numpy
  import numpy.linalg
  from numpy.lib.array_utils import normalize_axis_index
  from .None import polyutils
  from ._polybase import ABCPolyBase
label_desc: Use image node_id 12 for calling a global function with example usage: chebsub(c1, c2) and returns: pu