1. Languages

Everything is based on languages! We can't talk about anything without at least one description. A description is a text (a set of symbols) governed by rules (a grammar) stipulating what can and cannot be legally expressed. In addition to these syntactic conventions, a semantic system is required to give meaning to what is written.

It is from this meaning that we can reason – to write a text that provides a certain effect, – to know whether a goal is achievable, – to determine whether two utterances are similar, etc. Semantics are themselves texts written (mostly) in English (in standards, recommendations, RFCs, etc.) or in formal systems (BNF, W-grammar, lambda-calculus, natural semantics, pseudo-code, etc.), the latter being themselves, in turn, governed by grammar and semantics.

Syntax and semantics are often accompanied by pragmatics,...