def is_alias_assignment(expr):
    """
    Examples:
    ['=', 'column_name', 1]                                       Constant assignment
    ['=', 'column_name', 'other_column']                          Basic aliasing
    ['=', 'column_name', ['sin', 'column_name']]
    ['=', 'column_name', ['+', 'column_name', 'other_column']]    Complex calculations
    """
    return type(expr) is list and len(expr) == 3 and expr[0] == '='