code: def pow_simplify(expr):
      if str(expr[0])[:5] != "#CPow":
          return None
      if str(expr[1][0])[:5] != "#CPow":
          return None
  
      op_power = float(expr[0][5:])
      sub_power = float(expr[1][0][5:])
      new_power = sub_power * op_power
      if new_power == 1.0:
          return expr[1][1]
      else:
          return ("#CPow%.4e" % new_power, expr[1][1])
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import numpy
  import tensorflow
label_desc: Use image node_id 9 for calling a global function with example usage: pow_simplify(expr) and returns: None, None, expr, unknown,  expr