What I cannot create, I do not understand - Richard Feynman

Most of the time, we end up being consumers of a language. Language creation is not something which many of us do as part of our daily job. And as such, we become consumers of using various concepts like types of a language, functions-as-first-class citizens, closures, let expressions, etc. But what are these? What is semantics behind them? And how do language creators enable a language to have these? Once we understand what these mean, we go beyond the language specific implementations and can be true polyglots who can think in terms of these composable abstractions.

This beginner focussed talk+demonstration hopes to clarify few fundamental concepts by building a language from the ground up. This talk has its foundations in a couple of academic courses which I got to be part of during 2012/2013.

Using Racket(a variant of Scheme) as a vehicle, a hypothesized programming language (MathL) is introduced with its specifications, syntax, and rules. And slowly this language is built up with more features.The language is realized via an interpreter/executor. [We would not be discussing compilers here].
Some tests also would be done which would help to verify the language implementation.