Followup to Fundamentals of Formalisation Level 3: Set Theoretic Relations and Enumerability. First Post.

The big ideas:

• Formal Semantics
• Model

To move to the next level you need to be able to:

• Evaluate the truth value of logical sentences in a given model.
• Build models for a set of logical sentences and then use those models to deduce information about the sentences.

Why this is important:

• An AI built on a formal system will reason based on some sort of proof and model theory. The former gives its methods of proof (which you’ll learn in the next chapter), and the latter its semantics.
• This level will give you your first sense of what models of logical sentences look like.

You can find the lesson in our ihatestatistics course.

For every lesson you have 2 options: do the whole thing, or skip to the questions and "challenges" in the end. The latter option is for those people that suspect they already know the subject. It serves as a means of verifying or falsifying this hypothesis.

Good luck!