It is sure, as you said, that human lanaguges have intrinsic ambiguities.
However, I am sorry to say, I don't think that is my own explanation. I am not capable of explaining such thing myself. I think it probably is a specification of C/C++.
I just try to make things clear.
I wrote in English because these discussions did not matter very much and provided opportunities for me to practise my terrible English.
Thank you.