class_docstr: An unevaluated inner product between a Bra and a Ket [1].
  
  Parameters
  ==========
  
  bra : BraBase or subclass
      The bra on the left side of the inner product.
  ket : KetBase or subclass
      The ket on the right side of the inner product.
  
  Examples
  ========
  
  Create an InnerProduct and check its properties:
  
      >>> from sympy.physics.quantum import Bra, Ket
      >>> b = Bra('b')
      >>> k = Ket('k')
      >>> ip = b*k
      >>> ip
      <b|k>
      >>> ip.bra
      <b|
      >>> ip.ket
      |k>
  
  In simple products of kets and bras inner products will be automatically
  identified and created::
  
      >>> b*k
      <b|k>
  
  But in more complex expressions, there is ambiguity in whether inner or
  outer products should be created::
  
      >>> k*b*k*b
      |k><b|*|k>*<b|
  
  A user can force the creation of a inner products in a complex expression
  by using parentheses to group the bra and ket::
  
      >>> k*(b*k)*b
      <b|k>*|k>*<b|
  
  Notice how the inner product <b|k> moved to the left of the expression
  because inner products are commutative complex numbers.
  
  References
  ==========
  
  .. [1] https://en.wikipedia.org/wiki/Inner_product
code: def bra(self):
      return self.args[0]
  
file_path: sympy/sympy/physics/quantum/innerproduct.py
imports: from sympy.core.expr import Expr
  from sympy.functions.elementary.complexes import conjugate
  from sympy.printing.pretty.stringpict import prettyForm
  from sympy.physics.quantum.dagger import Dagger
  from sympy.physics.quantum.state import KetBase, BraBase
label_desc: Use image node_id 2 for calling the InnerProduct obj's underlying member method code with example usage: obj.bra() and returns: self