user2994cb

9 ms·

31.
by user2994cb 7y ago
That emulator is from the very talented Matthew Godbolt of "Compiler Explorer" fame, by the way.
32.
by user2994cb 7y ago
Interesting - this comment was marked as 'dead' until I upvoted it - some sort of over-zealous spam filter misinterpreting "bbc"? I was a Spectrum guy myself, but I did write my first C program on an Acorn Workstation cl
33.
by user2994cb 7y ago
This would have made a nice scene in that awful Imitation Game film, unlike the rubbish they actually put in (as well as other tales of the real Turing - the gas mask worn during hay fever season, for example).
34.
by user2994cb 7y ago
In fact, there seems to be a lot of interesting things about 1729: https://en.wikipedia.org/wiki/1729_(number)
35.
by user2994cb 7y ago
Feynman even has his own 1729 anecdote: https://www.ee.ryerson.ca/~elf/abacus/feynman.html
36.
by user2994cb 7y ago
Indeed, though that's to the entire volume - I was trying to link directly to the individual Gentzen papers (though by the fairly slow download maybe they are being created dynamically). Thanks for the interesting blog piece though - m
37.
by user2994cb 7y ago
Sorry about that, works OK for me (FF 72.0.2/Ubuntu 19.10).
38.
by user2994cb 7y ago
And the same volume has his proof of the consistency of arithmetic: http://www.digizeitschriften.de/download/PPN266833020_0039/P...
39.
by user2994cb 7y ago
The paper referenced also defines Gentzen's sequent calculus, an even nicer formulation of logic: http://www.digizeitschriften.de/download/PPN266833020_0039/P...
40.
by user2994cb 7y ago
An FSA matcher will be O(M) - one state transition per input character.
41.
by user2994cb 7y ago
As does Javascript of course. On the other hand, IEEE754 guarantees correct rounding, so floating point operations on integral values will come out alright (additions and multiplications will be exact within a large range, and inexact divis
42.
by user2994cb 7y ago
To put the original in more context, David A. Moon is a major figure in the Lisp world: https://en.wikipedia.org/wiki/David_A._Moon
43.
by user2994cb 8y ago
You can construct the complex numbers quite nicely with Geometric Algebra: https://www.youtube.com/watch?v=PNlgMPzj-7Q
44.
by user2994cb 8y ago
It's true that the original non-recursive definition of Y doesn't typecheck in Haskell: Prelude> \f->(\x->f(x x))(\x->f(x x)) <interactive>:5:14: Occurs check: cannot construct the infinite type: r0 ~
45.
Turing: Rounding-Off Errors in Matrix Processes (1948) [pdf](academic.oup.com)
4 points by user2994cb 8y ago|0 comments
46.
by user2994cb 8y ago
Interesting stuff. Maybe there is a connection with the use of quaternion pairs to represent rotations in 4-space (as in the Coxeter paper).
47.
by user2994cb 8y ago
> Location: Los Angeles, Prague It's still a bit early if he's in LA, particularly as it's Sunday.
48.
by user2994cb 8y ago
I forgot to add (1945) to the title, apologies.
49.
by user2994cb 8y ago
Useful discussion on Stack Overflow: https://stackoverflow.com/questions/16198700/using-the-extra... Upshot: you can probably get away with it if you are careful to canonicalize pointers before using them.
50.
Quaternions and Reflections (1946) [pdf](math.utah.edu)
22 points by user2994cb 8y ago|6 comments
51.
by user2994cb 8y ago
I came across this series of YouTube videos by Aubrey Clayton on Bayesian Inference (based on Ed Jaynes' book, 'Probability Theory: The Logic of Science') that I thought explained the fundamental ideas extraordinarly well but
52.
Bayesian Inference Lectures [video](youtube.com)
3 points by user2994cb 8y ago|1 comments
53.
by user2994cb 8y ago
There is a neat way of doing this style of indexing using barycentric coordinates: https://www.shadertoy.com/view/MlVfzG
54.
by user2994cb 8y ago
Building a tagged architecture on top of a stock 64-bit system would be much easier than with 32 bits - current systems use 48 bits for addresses, which leaves plenty of bits left over for the tag (you could even represent all non-floating
55.
by user2994cb 8y ago
An interesting (later) paper about generating the Stern-Brocot tree and the Calkin-Wilf tree simultaneously from a sequence of 2x2 matrices: http://www.cs.nott.ac.uk/~psarb2/MPC/RecountingRationalsTwic...
56.
by user2994cb 8y ago
There is a neat derivation of this from the fact that reflection in a plane with unit normal Q can be represented as P -> QPQ with P and Q considered as pure quaternions (ie. no scalar part).
57.
by user2994cb 8y ago
Previous discussion: https://news.ycombinator.com/item?id=11560122 and Paul Hankin has some more thoughts on the subject: https://blog.paulhankin.net/fibonacci2/
58.
by user2994cb 8y ago
Something like this happened in 1944: crew bailed out from Dornier 217 over London, plane carried on north, landing by itself in the Milton Road allotments in Cambridge: https://www.asisbiz.com/il2/Do-217/Do-217-KG
59.
by user2994cb 9y ago
Dan Boneh's Cryptography Part I on Coursera. Will we ever get Part II? Enrolling for Sept 2018 according to Coursera.
60.
by user2994cb 9y ago
Just out of interest (I worked on a table-driven parser for SML a couple of decades ago) - what bits of ML syntax is giving you trouble? I remember one bit that (theoretically) needed unbounded lookahead, and user-defined infix operators we

More ›