Doubting Chats

Statements: Some mails are chats. All updates are chats. Conclusions: I. All mails being updates is a possibility. II. No update is a mail.

Cri-du-chat syndrome in humans is caused by the :

Cri-du-chat syndrome in humans is caused by

Cri-du chat is

Cri-du-chat syndrome in is caused by the :

Le-chat liers principle