def my_base_name(x): return x if isinstance(x, This) else base_name(x)
def base_name_differs(x, y): return base_name(x) != base_name(y)
def base_name_differs(x,y): return base_name(x) != base_name(y)
def my_base_name(x): return x if isinstance(x,This) else base_name(x)