code: def _is_strong_prp(n, a):
      s = bit_scan1(n - 1)
      a = pow(a, n >> s, n)
      if a == 1 or a == n - 1:
          return True
      for _ in range(s - 1):
          a = pow(a, 2, n)
          if a == n - 1:
              return True
          if a == 1:
              return False
      return False
  
imports: import sys
  import math
  import mpmath.libmp
label_desc: Use image node_id 17 for calling a global function with example usage: _is_strong_prp(n, a) and returns: False, True, True, False