code: def _log_sub_sign(logx: float, logy: float) -> Tuple[bool, float]:
      """Returns log(exp(logx)-exp(logy)) and its sign."""
      if logx > logy:
          s = True
          mag = logx + np.log(1 - np.exp(logy - logx))
      elif logx < logy:
          s = False
          mag = logy + np.log(1 - np.exp(logx - logy))
      else:
          s = True
          mag = -np.inf
  
      return s, mag
  
imports: import math
  from typing import Tuple, Union
  import numpy
  from scipy import special
  import six
label_desc: Use image node_id 3 for calling a global function with example usage: _log_sub_sign(logx, logy) and returns: s,  mag