Purpose of the book
The book intends to provide practical guide with a lot of images and diagrams about Smart Contract. Smart Contract itself evolving ideas, and there are seldom to see real-smart contract implementation. The reason is from Bitcoin's transaction malleability, and Ethereum is now alpha release status.
So on the book, the details will be changed more or less in each protocols in the future. However general landscape of Smart contracts won't change so much, it allows us to build reliable online apps and infrastructure on decentralized technologies.
From 2009, the disruptive innovation of Bitcoin, we can see the real implementation even if it's not secure. The idea is started from the Nick Szabo's http://szabo.best.vwh.net/smart_contracts_idea.html and populated by Vitalik Buterin's Ethereum whitepaper https://github.com/ethereum/wiki/wiki/White-Paper
The book's main purpose is to provide information about smart contracts with real-use-cases.