class_docstr: Compute the matrix exponential of a square array.
class_docstr_tok: ["Compute","the","matrix","exponential","of","a","square","array","."]
code: def grad(self, inputs, outputs):
      (A,) = inputs
      (g_out,) = outputs
      return [ExpmGrad()(A, g_out)]
  
imports: from __future__ import absolute_import, print_function, division
  import logging
  import warnings
  from six.moves import xrange
  import numpy
  from theano import tensor
  import theano.tensor
  from theano.tensor import as_tensor_variable
  from theano.gof import Op, Apply
label_desc: Use image node_id 3 for calling the Expm obj's underlying member method code with example usage: obj.grad(inputs, outputs) and returns: list