code: def failing_assumptions(expr, **assumptions):
      """
      Return a dictionary containing assumptions with values not
      matching those of the passed assumptions.
  
      Examples
      ========
  
      >>> from sympy import failing_assumptions, Symbol
  
      >>> x = Symbol('x', positive=True)
      >>> y = Symbol('y')
      >>> failing_assumptions(6*x + y, positive=True)
      {'positive': None}
  
      >>> failing_assumptions(x**2 - 1, positive=True)
      {'positive': None}
  
      If *expr* satisfies all of the assumptions, an empty dictionary is returned.
  
      >>> failing_assumptions(x**2, positive=True)
      {}
  
      """
      expr = sympify(expr)
      failed = {}
      for k in assumptions:
          test = getattr(expr, "is_%s" % k, None)
          if test is not assumptions[k]:
              failed[k] = test
      return failed
  
imports: from sympy.utilities.exceptions import sympy_deprecation_warning
  from .facts import FactRules, FactKB
  from .sympify import sympify
  from sympy.core.random import _assumptions_shuffle
  from sympy.core.assumptions_generated import generated_assumptions
label_desc: Use image node_id 5 for calling a global function with example usage: failing_assumptions(expr) and returns: failed