Adam, thank you for your opinion on my IQ!
Retarded as I am, please explain how the bank (which one?) can "deposit" BTC100 in the block chain if said bank does not own BTC 100 to clear the transaction.
Thank you in advance for your explanation!
The deposit (transfer of possession of the 100BTC) would be reflected in two places; in their books and in the block chain. According to the block chain, the bank owns the 100BTC. But according to the contract between the depositor and the bank, the depositor owns the 100BTC but consents to the bank lending all or a fraction of it out.