def Kronecker(a,b):
    """
    Kronecker delta function.
    
    Parameters
    ----------
    a: int
        first index
    b: int
        second index
        
    Returns
    -------
        Return value 0 if a and b are not equal; return value 1 if a and b 
        are equal.
    """
    if a == b:
        return 1
    else:
        return 0