carlehewitt

9 ms·

31.
by carlehewitt 8y ago
Yes, Actors are faster than CSP processes with channels because there is no required overhead in communications passing through channels. In fact, if a channel is desired it can be efficiently implemented as an Actor with put and get me
32.
Computer Science Relies on the Opposite of Gödel's Results(cacm.acm.org)
4 points by carlehewitt 8y ago|1 comments
33.
by carlehewitt 8y ago
Instances of the induction axiom are uncountable for the higher order theory of the natural numbers, which obviously means that they cannot be enumerated using the natural numbers. However, it is very easy to use the induction axiom in pro
34.
by carlehewitt 8y ago
Gödel's proposition "I'mUnprovable" cannot be constructed as a fixed point of P |-> ~|-P because ~|-P has order one greater than the order of P.
35.
by carlehewitt 8y ago
A reference is: Ludwig Wittgenstein. 1956. Remarks on the Foundations of Mathematics, Revised Edition Basil Blackwell. 1978. There is a discussion here: https://hal.archives-ouvertes.fr/hal-01566393
36.
by carlehewitt 8y ago
The axioms of the higher order theory of the natural numbers are not countable and consequently not computationally enumerable. For example, there are uncountable many instances of the higher order induction axiom. Consequently, there are
37.
by carlehewitt 8y ago
The 1st order variant of the Dedekind/Peano theory of natural numbers is not suitable for computer science because it allows infinite integers and other monsters. See the following: https://cacm.acm.org/blogs/blog-
38.
by carlehewitt 8y ago
Of course, [Dedekind 1888] famously proved that the higher order theory characterized the natural numbers up to a unique isomorphism, which is impossible in the first order variant of this theory, which was developed later. Proof checking i
39.
by carlehewitt 8y ago
Godel's results are for the 1st order variant of the Dedekind/Peano theory of the natural numbers. Consequently, there is no contradiction with the inferential completeness (every proposition is provable or disprovable) or self-p
40.
by carlehewitt 8y ago
The Dedekind/Peano higher order theory of the natural numbers prove its own formal consistency. In this theory, proof checking is computationally decidable even though the theorems are not computationally enumerable by a total procedur
41.
by carlehewitt 8y ago
As Wittgenstein correctly pointed out, Gödel's proposition "I'm unprovable" is not a proposition in Russell's system because it leads to inconsistency. Consequently, Gödel's incompleteness results are not vali
42.
by carlehewitt 8y ago
Chaitin [2007] presented the following analysis: Godel's proof of inferential undecidability [incompleteness] was too superficial. It didn't get at the real heart of what was going on. It was more tantalizing than anything else. I
43.
by carlehewitt 8y ago
See the following for history and limitations of Godel's results: https://hal.archives-ouvertes.fr/hal-01566393
44.
What Turing and Church left out(cacm.acm.org)
5 points by carlehewitt 8y ago|0 comments
45.
Computer Science Encyclopedia Can Fill a Gap(cacm.acm.org)
80 points by carlehewitt 8y ago|29 comments
46.
by carlehewitt 8y ago
As explained in the articles referenced, Actor systems have unbounded nondeterminism because of indeterminacy. No "hypercomputation" is required ;-)
47.
by carlehewitt 8y ago
SCTB is correct. Sticking to the subject matter is the way to go. IMODE: Which part of the Actor Model theory of computation do you not understand?
48.
by carlehewitt 8y ago
In almost all current frameworks. every Actor has a mailbox. It makes very good sense for an Actor programming language not to have mailboxes built into every Actor because it can make programs less robust, more difficult to understand, and
49.
by carlehewitt 8y ago
The relationship with theories of information is explained in Strong Types for Direct Logic here: https://hal.archives-ouvertes.fr/hal-01566393
50.
by carlehewitt 8y ago
Jean is correct! Of course, unbounded nondeterminism is a somewhat artificial example. However, the extra power of Actors over Turing Machines is critical for IoT and the implementation of Intelligent Systems.
51.
by carlehewitt 8y ago
Message passing was omitted from the Turing Model. (Two Turing Machines cannot send messages to each other.) Message passing is fundamental for IoT, etc.
52.
by carlehewitt 8y ago
The Actor Model covers all digital computations. Actor programming languages can express all computations in the Actor Model.
53.
by carlehewitt 8y ago
Message passing communication is more fundamental than channel commutation. However, lists {T*] of type T are very important; especially when they are used with Futures.
54.
by carlehewitt 8y ago
Thanks! Additional information that you might find helpful is here: https://plus.google.com/+CarlHewitt-StandardIoT
55.
by carlehewitt 8y ago
You can watch the keynotes for free after the conference :-)
56.
by carlehewitt 8y ago
Correct. Current implementations are inadequate :-( There is a Silicon Valley startup working on one that should be adequate :-)
57.
by carlehewitt 8y ago
Fowler's talk addressed issues arising from "mixing metaphors" by having both channels and Actors in our programming languages. The point of this post is to point out that channels are best understood as Actors that take put
58.
by carlehewitt 8y ago
PS. The interface for ReadersWriter is Interface ReadersWriter read[QueryRequest] -> QueryResponse, write[WriteRequest] -> Void A ReadersWriter scheduler for a database allows multiple read messages to be conc
59.
Strong Types for Direct Logic(drive.google.com)
2 points by carlehewitt 8y ago|1 comments
60.
Channels are Actors
24 points by carlehewitt 8y ago|18 comments

More ›