Expert systems

Systems that use rules, facts, and inferrence to determine an outcome. Their success is debatable, with knowledge acquisition and actually getting the experts to write down the facts/rules being the chief problems. This could be useful for personal projects, but ultimately requires competence and time.

Books

• Introduction To Expert Systems (3rd Edition) 3rd Edition by Peter Jackson
• Expert Systems: Principles and Programming, Fourth Edition by Joseph C. Giarratano

Declarative programming

When/Then vs If/Then

When/Then is where you state what needs to be done, not how it needs to be done. This allows delegation of the ordering and figuring out dependencies to another system.

When
    Conditions
Then
    Actions

Rules are represented by the antecedent (aka left-handed side) which is the conditions of a rule. The consequent (aka right hand side) are the actions of the rule.

Forward-chaining and backwards-chaining

Forward-chaining systems start with a premises and work forward to the conclusions supported by those premises. Backward-chaining systems start with a conclusion to be proved and work backward to the premises that would support the conclusion. There are also systems that are a hybrid of both.