Personal agents: What are expert systems? Do expert systems benefit from decentralization
Personal agents: What are expert systems? Do expert systems benefit from decentralization?
In my previous blog post titled "[The value of Knowledge Representation and the Decentralized Knowledge Base for Artificial Intelligence (expert systems)](https://steemit.com/ai/@dana-edwards/the-value-of-knowledge-representation-and-the-decentralized-knowledge-base-for-artificial-intelligence-expert-systems)" I discussed the first piece of a larger puzzle. Knowledge representation and a shared knowledge base were both explained. The purpose of that blogpost was to destribe the concepts of knowledge representation and the knowledge base but also to show why both are valuable for artificial intelligence. This particular article will explain the concept of an expert system and then I will discuss some possible ideas for what can be built in a decentralized AI context.
The recipe for building an expert system
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An expert system has two core components which include 1) a knowledge base, 2) an inference engine (semantic reasoner). An expert system is a computer system which emulates the decision making capability of a human expert by reasoning about knowledge and applying rules. Implication for example is a rule which leads to if...then... (otherwise recognized as if p then q). In a computer programming language we would call this set of "if then" statements our [conditionals](https://en.wikipedia.org/wiki/Conditional_%28computer_programming%29) . Conditionals are familiar to anyone who knows C, C++, JAVA, Python, or any typical programming language and this basic structure comes from logic.
We can recognize that conditionals are a set of rules which can be mapped on a flow chart like this: 
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Expert systems are rule based AI
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Just as we can see how if-then-else can become a structure of rules, the expert systems are entirely rule based.
An expert system which has a knowledge base to work with may rely on a goal tree.
Expert systems are fundamentally weak AI. They cannot be self aware or conscious as they are simply mechanical sets of rules being applied according to logic on a knowledge base. Expert systems may exhibit intelligent behavior which is to say they are intelligent tools. This may be enough however to achieve the goals and you can have personal agents which can behave intelligently using an expert system approach.
Trees, trees, and more trees
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Now we know how to create an expert system built from a knowledge base and a reasoner. To understand what the future holds for decentralized AI I must briefly discuss the concept of trees. Trees can possibly be infinite structures. Higher order model checking for those familiar with model checking is a form of model checking which can work over infinite structures such as the infinite tree via higher order recursion schemes. Why is any of this important?
Program verification, program analysis, can work when you think of the fact that any program can be represented as a tree. This is important for the security guarantees and for correctness guarantees. In the case where you would like to approach decentralization of AI then you ultimately will have to work with trees and for that reason I discuss it.
Decentralized knowledge base + distributed contribution via knowledge representation language
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In order to build a decentralized AI it will be important to have a decentralized knowledge base. The main problem is growing the knowledge base large enough that an expert system can become smart. In a decentralized context you can have in theory anyone in the world contribute to the collective decentralized knowledge base. Decentralization of the knowledge base would make it more resilient in the case of an attack, a nuclear apocalypse or similar scenarios like that which necessitated decentralization of the Internet. From a cyber security perspective human knowledge is safest if decentralized.
Sensors are essentially everywhere, big data is essentially here, but the decentralized knowledge base doesn't exist. We have Google which wants to be at best a centralized knowledge base. Google has AI but it will at best be centralized. A decentralized AI based on expert systems can function similar to that which has been described already as the semantic web but with some improvements.
Your own army of personal experts
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If everything goes right in a decentralized context then each person will have access to intelligent agents. These agents will be able to reason over a knowledge base and act as an expert system. For very difficult tasks the computation resources could be rented and paid for via a token. Verified computation and model checking can allow for many machines to compute on your behalf but with a minimized security risk as you would have formal verification built in.
What is the conclusion here?
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Expert systems can be built in a decentralized context. Decentralized AI is theoretically possible and likely to be built sooner or later. Decentralized AI can be safer than centralized depending on the use case and it can also be much more efficient depending on the circumstances. For example if computation can be sold on a market then in theory if a million PC owners rent their computation out for a token then you in essence have the cheapest super computer in the world. Will it be good at everything? Perhaps not, but for certain kinds of computation it will be the most cost effective.
Bots will become much more powerful, more capable, with an ability to be experts and make intelligent decisions. This will have both positive and negative consequences depending on the safe guards and governance capabilities in place. If there are no safe guards at all then this could be both a new frontier and present new dangers. At the same time if there are some safe guards and ethical governance then this could provide many new opportunities and possibly boost the economy in new ways. In fact, the ability to have this AI can improve not just reasoning ability, but decision making abilities too, and that can allow for moral augmentation along with improved governance.