(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
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.
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 .
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
def epsilon ( i , j , k ) : 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