code: def test_torf():
      v = [T, F, U]
      for i in product(*[v] * 3):
          assert _torf(i) is (
              True
              if all(j for j in i)
              else (False if all(j is False for j in i) else None)
          )
  
file_path: sympy/sympy/core/tests/test_logic.py
imports: from sympy.core.logic import fuzzy_not, Logic, And, Or, Not, fuzzy_and, fuzzy_or, _fuzzy_group, _torf, fuzzy_nand, fuzzy_xor
  from sympy.testing.pytest import raises
  from itertools import product
label_desc: Use image node_id 1 for calling a global function with example usage: test_torf() without return types