code: def get_known_facts_keys():
      """
      Return every unary predicates registered to ``Q``.
  
      This function is used to generate the keys for
      ``generate_known_facts_dict``.
  
      """
      exclude = set()
      for pred in [Q.eq, Q.ne, Q.gt, Q.lt, Q.ge, Q.le]:
          # exclude polyadic predicates
          exclude.add(pred)
  
      result = []
      for attr in Q.__class__.__dict__:
          if attr.startswith("__"):
              continue
          pred = getattr(Q, attr)
          if pred in exclude:
              continue
          result.append(pred)
      return result
  
file_path: sympy/sympy/assumptions/facts.py
imports: from sympy.assumptions.ask import Q
  from sympy.assumptions.assume import AppliedPredicate
  from sympy.core.cache import cacheit
  from sympy.core.symbol import Symbol
  from sympy.logic.boolalg import to_cnf, And, Not, Implies, Equivalent, Exclusive
  from sympy.logic.inference import satisfiable
label_desc: Use image node_id 6 for calling a global function with example usage: get_known_facts_keys() and returns: result