code: def test_AccumBounds_exponent():
      # base is 0
      z = 0 ** B(a, a + S.Half)
      assert z.subs(a, 0) == B(0, 1)
      assert z.subs(a, 1) == 0
      p = z.subs(a, -1)
      assert p.is_Pow and p.args == (0, B(-1, -S.Half))
      # base > 0
      #   when base is 1 the type of bounds does not matter
      assert 1 ** B(a, a + 1) == 1
      #  otherwise we need to know if 0 is in the bounds
      assert S.Half ** B(-2, 2) == B(S(1) / 4, 4)
      assert 2 ** B(-2, 2) == B(S(1) / 4, 4)
  
      # +eps may introduce +oo
      # if there is a negative integer exponent
      assert B(0, 1) ** B(S(1) / 2, 1) == B(0, 1)
      assert B(0, 1) ** B(0, 1) == B(0, 1)
  
      # positive bases have positive bounds
      assert B(2, 3) ** B(-3, -2) == B(S(1) / 27, S(1) / 4)
      assert B(2, 3) ** B(-3, 2) == B(S(1) / 27, 9)
  
      # bounds generating imaginary parts unevaluated
      assert unchanged(Pow, B(-1, 1), B(1, 2))
      assert B(0, S(1) / 2) ** B(1, oo) == B(0, S(1) / 2)
      assert B(0, 1) ** B(1, oo) == B(0, oo)
      assert B(0, 2) ** B(1, oo) == B(0, oo)
      assert B(0, oo) ** B(1, oo) == B(0, oo)
      assert B(S(1) / 2, 1) ** B(1, oo) == B(0, oo)
      assert B(S(1) / 2, 1) ** B(-oo, -1) == B(0, oo)
      assert B(S(1) / 2, 1) ** B(-oo, oo) == B(0, oo)
      assert B(S(1) / 2, 2) ** B(1, oo) == B(0, oo)
      assert B(S(1) / 2, 2) ** B(-oo, -1) == B(0, oo)
      assert B(S(1) / 2, 2) ** B(-oo, oo) == B(0, oo)
      assert B(S(1) / 2, oo) ** B(1, oo) == B(0, oo)
      assert B(S(1) / 2, oo) ** B(-oo, -1) == B(0, oo)
      assert B(S(1) / 2, oo) ** B(-oo, oo) == B(0, oo)
      assert B(1, 2) ** B(1, oo) == B(0, oo)
      assert B(1, 2) ** B(-oo, -1) == B(0, oo)
      assert B(1, 2) ** B(-oo, oo) == B(0, oo)
      assert B(1, oo) ** B(1, oo) == B(0, oo)
      assert B(1, oo) ** B(-oo, -1) == B(0, oo)
      assert B(1, oo) ** B(-oo, oo) == B(0, oo)
      assert B(2, oo) ** B(1, oo) == B(2, oo)
      assert B(2, oo) ** B(-oo, -1) == B(0, S(1) / 2)
      assert B(2, oo) ** B(-oo, oo) == B(0, oo)
  
imports: from sympy.core.numbers import E, Rational, oo, pi, zoo
  from sympy.core.singleton import S
  from sympy.core.symbol import Symbol
  from sympy.functions.elementary.exponential import exp, log
  from sympy.functions.elementary.miscellaneous import Max, Min, sqrt
  from sympy.functions.elementary.trigonometric import cos, sin, tan
  from sympy.calculus.accumulationbounds import AccumBounds
  from sympy.core import Add, Mul, Pow
  from sympy.core.expr import unchanged
  from sympy.testing.pytest import raises, XFAIL
  from sympy.abc import x
label_desc: Use image node_id 8 for calling a global function with example usage: test_AccumBounds_exponent() without return types