Intro to Lambda Calculus: Syntax, evaluation, terminology (compared to Haskell, Python, JavaScript)

A practical introduction to the lambda calculus, covering the basics of syntax compared to Haskell, OCaml, JavaScript and Python (showing variables, function application and function abstraction) and how we evaluate it (with beta-reduction / β-reduction). Ends with 4 worked exercises to develop familiarity with the syntax.

00:00 What is the Lambda calculus
00:23 Example: The identity function applied to 3
04:09 Other notations for the lambda calculus
04:52 Exercise 1: Breaking down an expression
05:49 Exercise 2: Evaluating an expression
06:40 Exercise 3: Breaking down an expression
08:20 Exercise 4: Evaluating an expression
10:05 Where do we go from here?

[daviddawkins]

Many thanks for this series, I'm currently learning how to implement HM. Great first video

[asitisj]

6:26
I d not had seen how
(\1 - > ( x- > 1)) 2
reduce to 2nd expression here, unless i knew that if you apply the lambda expression to two values, you return the first value

[TheOiseau]

Something that's never explained with these videos, is _why_ anyone would choose to write the obscure:

(\odd --> odd 3) (\x --> equals (mod x 2) 1)

instead of the clear as day:

if (x mod 2 == 1) return true;

Is it just for nerd credentials?