understanding gnucash xml files

[Peter von Kaehne]

In reference to my other thread, this is just a short question to
confirm:

Is each gnc:transaction item atomic and entirely self-reliant? 

My impression is that it is. It seems that each transaction has a id
which is (random(?)) lengthy number, it references the two accounts it
refers to by their id but otherwise it has no connection to other
gnc:transaction items or indeed any other items. Balances are created on
the fly by Gnucash and are not anywhere stored.

Is this correct?