I have learned in school that じゃ ありましん is the "non-past negative" conjugation of です.
"I am not Japanese."
I have noticed that じゃ ありません contains the pronunciation of the negative form of あります.
From a strictly grammatical point of view, does じゃ ありません say that something doesn't exist? If so, what is the grammatical purpose of attaching じゃ to the proceeding word?