Re:λ Calculus [pdf]
by cloudripper on Thursday August 17, 2023 @11:36PM
(#37171157)
Thanks for sharing. He makes the material very interesting and very accessible. I've fallen into another HN rabbithole..
Re:λ Calculus [pdf]
by photochemsyn on Thursday August 17, 2023 @11:43PM
(#37171185)
That looks interesting, although it is 3 hrs. I like this ~45 minute intro to the concept, which seems a little more Turing-accesible:, in that it shows how you can implement addition and multiplication in the system, which is a lot:
successor function: given a number, get the next number
try this in Python:
zero = lambda f: lambda x: x
one = lambda f: lambda x: f(x)
two = lambda f: lambda x: f(f(x))
to_int = lambda n: n(lambda i: i+1)(0)
succ = lambda n: lambda f: lambda x: f(n(f)(x))
three = succ(two)
four = succ(three)
to_int(four)
So that's just counting, the Church Numerals, where it begins.
Re:λ Calculus [pdf]
by throwawaylinux on Friday August 18, 2023 @12:36AM
(#37171449)
What's Turing-accesible?
This is another excellent video if you are more of a Javascript developer: https://www.youtube.com/watch?v=OLH3L285EiY
(Sorry, I actually meant to post this video: https://www.youtube.com/watch?v=3VQ382QG-y4)
He does a wonderful job of taking very dense mathematical notation and explaining it in ways that anyone can understand. He derives the basic concepts of the lambda calculus from the ground up using Python. Super fun to follow along with.