class_docstr: A KB for Propositional Logic.  Inefficient, with no indexing.
class_docstr_tok: ["A","KB","for","Propositional","Logic",".","Inefficient",",","with","no","indexing","."]
docstr: Remove the sentence's clauses from the KB
  
  Examples
  ========
  
  >>> from sympy.logic.inference import PropKB
  >>> from sympy.abc import x, y
  >>> l = PropKB()
  >>> l.clauses
  []
  
  >>> l.tell(x | y)
  >>> l.clauses
  [x | y]
  
  >>> l.retract(x | y)
  >>> l.clauses
  []
docstr_tok: ["Remove","the","sentence","'s","clauses","from","the","KB","Examples","========",">",">",">","from","sympy.logic.inference","import","PropKB",">",">",">","from","sympy.abc","import","x",",","y",">",">",">","l","=","PropKB","(",")",">",">",">","l.clauses","[","]",">",">",">","l.tell","(","x","|","y",")",">",">",">","l.clauses","[","x","|","y","]",">",">",">","l.retract","(","x","|","y",")",">",">",">","l.clauses","[","]"]
code: def retract(self, sentence):
      """Remove the sentence's clauses from the KB
  
      Examples
      ========
  
      >>> from sympy.logic.inference import PropKB
      >>> from sympy.abc import x, y
      >>> l = PropKB()
      >>> l.clauses
      []
  
      >>> l.tell(x | y)
      >>> l.clauses
      [x | y]
  
      >>> l.retract(x | y)
      >>> l.clauses
      []
  
      """
      for c in conjuncts(to_cnf(sentence)):
          self.clauses_.discard(c)
  
imports: from sympy.logic.boolalg import And, Not, conjuncts, to_cnf, BooleanFunction
  from sympy.core.sorting import ordered
  from sympy.core.sympify import sympify
  from sympy.external.importtools import import_module
label_desc: Use image node_id 3 for calling the PropKB obj's underlying member method code with example usage: obj.retract(sentence) without return types