code: def delta(i, j):
      """
      Returns 1 if ``i == j``, else 0.
  
      This is used in the multiplication of Pauli matrices.
  
      Examples
      ========
  
      >>> from sympy.physics.paulialgebra import delta
      >>> delta(1, 1)
      1
      >>> delta(2, 3)
      0
      """
      if i == j:
          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 1 for calling a global function with example usage: delta(i, j) and returns: int, int