code: def epsilon(i, j, k):
      """
      Return 1 if i,j,k is equal to (1,2,3), (2,3,1), or (3,1,2);
      -1 if ``i``,``j``,``k`` is equal to (1,3,2), (3,2,1), or (2,1,3);
      else return 0.
  
      This is used in the multiplication of Pauli matrices.
  
      Examples
      ========
  
      >>> from sympy.physics.paulialgebra import epsilon
      >>> epsilon(1, 2, 3)
      1
      >>> epsilon(1, 3, 2)
      -1
      """
      if (i, j, k) in ((1, 2, 3), (2, 3, 1), (3, 1, 2)):
          return 1
      elif (i, j, k) in ((1, 3, 2), (3, 2, 1), (2, 1, 3)):
          return -1
      else:
          return 0
  
file_path: sympy/sympy/physics/paulialgebra.py
imports: from sympy.core.add import Add
  from sympy.core.mul import Mul
  from sympy.core.numbers import I
  from sympy.core.power import Pow
  from sympy.core.symbol import Symbol
  from sympy.physics.quantum import TensorProduct
label_desc: Use image node_id 2 for calling a global function with example usage: epsilon(i, j, k) and returns: int, unknown, int