code: def not_(a):
      """Functional form of "not"."""
      if tensor_util.is_tf_type(a):
          return _tf_not(a)
      return _py_not(a)
  
file_path: tensorflow-upstream/tensorflow/python/autograph/operators/logical.py
imports: from tensorflow.python.framework import tensor_util
  from tensorflow.python.ops import cond
  from tensorflow.python.ops import gen_math_ops
label_desc: Use image node_id 1 for calling a global function with example usage: not_(a) and returns: _py_not, _tf_not