code: def test_validate_bad(self):
      f, g, h = self.f, self.g, self.h
  
      # Too few inputs.
      with self.assertRaises(ValueError):
          NumericalExpression("x_0", (), dtype=float64_dtype)
      with self.assertRaises(ValueError):
          NumericalExpression("x_0 + x_1", (f,), dtype=float64_dtype)
  
      # Too many inputs.
      with self.assertRaises(ValueError):
          NumericalExpression("x_0", (f, g), dtype=float64_dtype)
      with self.assertRaises(ValueError):
          NumericalExpression(
              "x_0 + x_1", (f, g, h), dtype=float64_dtype
          )
  
      # Invalid variable name.
      with self.assertRaises(ValueError):
          NumericalExpression("x_0x_1", (f,), dtype=float64_dtype)
      with self.assertRaises(ValueError):
          NumericalExpression("x_0x_1", (f, g), dtype=float64_dtype)
  
      # Variable index must start at 0.
      with self.assertRaises(ValueError):
          NumericalExpression("x_1", (f,), dtype=float64_dtype)
  
      # Scalar operands must be numeric.
      with self.assertRaises(TypeError):
          "2" + f
      with self.assertRaises(TypeError):
          f + "2"
      with self.assertRaises(TypeError):
          f > "2"
  
      # Boolean binary operators must be between filters.
      with self.assertRaises(TypeError):
          f + (f > 2)
      with self.assertRaises(TypeError):
          (f > f) > f
  
imports: from itertools import permutations
  from operator import add, ge, gt, le, lt, methodcaller, mul, ne, sub
  from string import ascii_uppercase
  from unittest import TestCase
  import numpy
  from numpy import arange, array, eye, float64, full, isnan, zeros
  from pandas import DataFrame, date_range, Int64Index
  from catalyst.pipeline import Factor, Filter
  from catalyst.pipeline.expression import NumericalExpression, NUMEXPR_MATH_FUNCS
  from catalyst.testing import check_allclose
  from catalyst.utils.numpy_utils import datetime64ns_dtype, float64_dtype
label_desc: Use image node_id 5 for calling the NumericalExpressionTestCase obj's underlying member method code with example usage: obj.test_validate_bad() without return types