class_docstr: Logarithm of the sum of exponentiations of the inputs.
  
  Helper class for use with e.g. numpy.logaddexp
  
  See Also
  ========
  
  https://numpy.org/doc/stable/reference/generated/numpy.logaddexp.html
docstr: Returns the first derivative of this function.
docstr_tok: ["Returns","the","first","derivative","of","this","function","."]
code: def fdiff(self, argindex=1):
      """
      Returns the first derivative of this function.
      """
      if argindex == 1:
          wrt, other = self.args
      elif argindex == 2:
          other, wrt = self.args
      else:
          raise ArgumentIndexError(self, argindex)
      return S.One / (S.One + exp(other - wrt))
  
imports: from sympy.core.function import Add, ArgumentIndexError, Function
  from sympy.core.power import Pow
  from sympy.core.singleton import S
  from sympy.core.sorting import default_sort_key
  from sympy.functions.elementary.exponential import exp, log
label_desc: Use image node_id 2 for calling the logaddexp obj's underlying member method code with example usage: obj.fdiff(argindex) and returns: unknown