code: def _(expr, assumptions):
      """
      Return True if expr is bounded, False if not and None if unknown.
  
      Truth Table:
  
      +---+---+---+--------+
      |   |   |   |        |
      |   | B | U |   ?    |
      |   |   |   |        |
      +---+---+---+---+----+
      |   |   |   |   |    |
      |   |   |   | s | /s |
      |   |   |   |   |    |
      +---+---+---+---+----+
      |   |   |   |        |
      | B | B | U |   ?    |
      |   |   |   |        |
      +---+---+---+---+----+
      |   |   |   |   |    |
      | U |   | U | U | ?  |
      |   |   |   |   |    |
      +---+---+---+---+----+
      |   |   |   |        |
      | ? |   |   |   ?    |
      |   |   |   |        |
      +---+---+---+---+----+
  
          * B = Bounded
  
          * U = Unbounded
  
          * ? = unknown boundedness
  
          * s = signed (hence nonzero)
  
          * /s = not signed
      """
      result = True
      for arg in expr.args:
          _bounded = ask(Q.finite(arg), assumptions)
          if _bounded:
              continue
          elif _bounded is None:
              if result is None:
                  return None
              if ask(Q.extended_nonzero(arg), assumptions) is None:
                  return None
              if result is not False:
                  result = None
          else:
              result = False
      return result
  
file_path: sympy/sympy/assumptions/handlers/calculus.py
imports: from sympy.assumptions import Q, ask
  from sympy.core import Add, Mul, Pow, Symbol
  from sympy.core.numbers import NegativeInfinity, GoldenRatio, Infinity, Exp1, ComplexInfinity, ImaginaryUnit, NaN, Number, Pi, E, TribonacciConstant
  from sympy.functions import cos, exp, log, sign, sin
  from sympy.logic.boolalg import conjuncts
  from ..predicates.calculus import FinitePredicate, InfinitePredicate, PositiveInfinitePredicate, NegativeInfinitePredicate
label_desc: Use image node_id 3 for calling a global function with example usage: _(expr, assumptions) and returns: result, None, None