code: def find_degree(M, deg_f):
      """
      Finds the degree of the poly corresponding (after triangularization)
      to the _last_ row of the ``small'' matrix M, created by create_ma().
  
      deg_f is the degree of the divident poly.
      If _last_ row is all 0's returns None.
  
      """
      j = deg_f
      for i in range(0, M.cols):
          if M[M.rows - 1, i] == 0:
              j = j - 1
          else:
              return j if j >= 0 else 0
  
imports: from sympy.concrete.summations import summation
  from sympy.core.function import expand
  from sympy.core.numbers import nan
  from sympy.core.singleton import S
  from sympy.core.symbol import Dummy
  from sympy.functions.elementary.complexes import Abs, sign
  from sympy.functions.elementary.integers import floor
  from sympy.matrices.dense import eye, Matrix, zeros
  from sympy.printing.pretty.pretty import pretty_print
  from sympy.simplify.simplify import simplify
  from sympy.polys.domains import QQ
  from sympy.polys.polytools import degree, LC, Poly, pquo, quo, prem, rem
  from sympy.polys.polyerrors import PolynomialError
label_desc: Use image node_id 34 for calling a global function with example usage: find_degree(M, deg_f) and returns: unknown