- int or int32_t (was Re: Why do some people hate namespace prefixes?) - 6 Updates
- Eliminating Undecidability and Incompleteness in Formal Systems (Prolog already does this) - 9 Updates
- "Modern C++ Won't Save Us" by alex_gaynor - 4 Updates
- How to write program to find bonus? - 2 Updates
- "Modern C++ Won't Save Us" by alex_gaynor - 1 Update
| Mr Flibble <flibble@i42.removethisbit.co.uk>: Apr 27 01:14AM +0100 On 26/04/2019 23:27, Ian Collins wrote: >> integer typedefs citing reasons including portability and safety. > A somewhat dubious requirement which leads to silliness such as uin8_t > loop counters and portability performance problems. Nonsense. /Flibble -- "You won't burn in hell. But be nice anyway." – Ricky Gervais "I see Atheists are fighting and killing each other again, over who doesn't believe in any God the most. Oh, no..wait.. that never happens." – Ricky Gervais "Suppose it's all true, and you walk up to the pearly gates, and are confronted by God," Bryne asked on his show The Meaning of Life. "What will Stephen Fry say to him, her, or it?" "I'd say, bone cancer in children? What's that about?" Fry replied. "How dare you? How dare you create a world to which there is such misery that is not our fault. It's not right, it's utterly, utterly evil." "Why should I respect a capricious, mean-minded, stupid God who creates a world that is so full of injustice and pain. That's what I would say." |
| Ian Collins <ian-news@hotmail.com>: Apr 27 12:22PM +1200 On 27/04/2019 12:14, Mr Flibble wrote: >> A somewhat dubious requirement which leads to silliness such as uin8_t >> loop counters and portability performance problems. > Nonsense. Seen it mate! -- Ian. |
| Bonita Montero <Bonita.Montero@gmail.com>: Apr 27 06:23PM +0200 > And where exactly are you going to search for its documentation, if you > don't even know if it's a custom function or a standard library function? I right-click at the symbol in my IDE and then click "go to definition". |
| Bonita Montero <Bonita.Montero@gmail.com>: Apr 27 08:55PM +0200 > uint32_t may carry significant overheads if the compiler has to mess > about with packing/unpacking it from some different size native word. Pure theory. |
| Robert Wessel <robertwessel2@yahoo.com>: Apr 27 03:33PM -0500 On Sat, 27 Apr 2019 10:27:34 +1200, Ian Collins <ian-news@hotmail.com> wrote: >> integer typedefs citing reasons including portability and safety. >A somewhat dubious requirement which leads to silliness such as uin8_t >loop counters and portability performance problems. I agree, but wouldn't the correct type to use for such a thing be uint_fast8_t rather than unit8_t? |
| Bart <bc@freeuk.com>: Apr 28 12:04AM +0100 On 27/04/2019 21:33, Robert Wessel wrote: >> loop counters and portability performance problems. > I agree, but wouldn't the correct type to use for such a thing be > uint_fast8_t rather than unit8_t? How about just 'byte'? That's a little more snappy. Can't be many people who don't know what a byte is (they will know it's 8 bits, and I believe more regard it as unsigned than signed). It be helpful that it's easier to type, given the two typos involving 'uint8_t' above. However I keep forgetting this is C++ where such things as clear syntax are very low on the list of priorities. |
| Kaz Kylheku <847-115-0292@kylheku.com>: Apr 27 01:13AM ["Followup-To:" header set to comp.lang.lisp.] >> he doesn't know what a counter-example is, and such. > I have come a very long way since the last time that we talked four > years ago. If you aren't doing this in some kind of Lisp, though, it's off topic in comp.lang.lisp. > deductive inference model: > Then True(X) means Provable(X) and False(X) mean Provable(¬X) Leaving > everything else as Unsound(X). If all truths are provable, and anything not provable is false, then the system has been weakened; it is incomplete. Gödel's work is not restricted to examining the properties of a system which conforms to these constraints; it speaks about a more general system in which a truth can be unprovable. (You can wish that that system didn't exist, but that doesn't make it go away.) Similarly, in computing, we could restrict ourselves to a programming language that has only bounded loops and no recursion. Then claim, look, everything halts! Everything surely halts in that language which conforms to those restrictions, but not in a model of computation that doesn't have those restrictions. That's all I'm going to say on the subject, except for this: If True(X) means Provable(X), and only *only* True(X) means that, then that means your system has no axioms; how can it exist and do anything useful? Formal systems require axioms: the basic propositions that are painted as true rather than proven, from which other things follow. "Provable" is synonymous with "derivable from axioms". How could you have forgotten these? Gödel's work informs us, essentially, that the syntax of formal systems is capable of expressing new axioms. These are well-formed statements which do not conflict with any of the existing axioms, yet which we are not able to derive from those axioms either: they relate to the existing axioms in the same way that those axioms to each other. (Just like Euclid's Fifth Postulate can't be proven from the other four. It either has to be accepted, rejected (resulting in a weaker form of geometry) or replaced with different versions (leading to alternative geometries). Contrary to your past claims, you have not found a devastating mistake in Gödel's work; nobody has. It stands. |
| Keith Thompson <kst-u@mib.org>: Apr 26 07:43PM -0700 > Prolog already implements the sound deductive inference model. [...] > This simple little system shows that Gödel's Incompleteness Theorem > and the Tarski Undefinability Theorem are false. [...] Please restrict followups to relevant newsgroups. In particular, this is off topic in comp.lang.c++ and comp.lang.c, and probably in comp.lang.lisp as well. -- Keith Thompson (The_Other_Keith) kst-u@mib.org <http://www.ghoti.net/~kst> Will write code for food. void Void(void) { Void(); } /* The recursive call of the void */ |
| peteolcott <Here@Home>: Apr 27 11:23AM -0500 On 4/26/2019 8:13 PM, Kaz Kylheku wrote: >> everything else as Unsound(X). > If all truths are provable, and anything not provable is false, then the > system has been weakened; it is incomplete. That is nothing like what I just said. > Gödel's work is not restricted to examining the properties of > a system which conforms to these constraints; it speaks about a more > general system in which a truth can be unprovable. Truth cannot possibly be unprovable in the sound deductive inference model. Within the sound deductive inference model there is a (connected sequence of valid deductions from true premises to a true conclusion) thus unlike the formal proofs of symbolic logic provability cannot diverge from truth. > as true rather than proven, from which other things follow. "Provable" > is synonymous with "derivable from axioms". How could you have > forgotten these? Formalizing the Sound Deductive Inference Model in Symbolic Logic Axiom(0) Stipulates** this definition of Axiom: Expressions of language defined to have the semantic value of Boolean True. Provides the symbolic logic equivalent of true premises. Stipulating** this specification of True and False: (TRUE ↔ ⊤ ∧ FALSE ↔ ⊥) Axiom(1) ∀F ∈ Formal_System ∀x ∈ Closed_WFF(F) (True(F, x) ↔ (F ⊢ x)) Axiom(2) ∀F ∈ Formal_System ∀x ∈ Closed_WFF(F) (False(F, x) ↔ (F ⊢ ¬x)) Thus stipulating** that consequences are provable from axioms. Stipulating** that formal systems are Boolean: Axiom(3) ∀F ∈ Formal_System ∀x ∈ Closed_WFF(F) (True(F,x) ∨ False(F,x)) Screens out semantically unsound sentences as not belonging to the formal system. -- Copyright 2019 Pete Olcott All rights reserved "Great spirits have always encountered violent opposition from mediocre minds." Albert Einstein |
| Kaz Kylheku <847-115-0292@kylheku.com>: Apr 27 06:26PM > Truth cannot possibly be unprovable in the sound deductive inference model. Again, only if it that model contains no axioms. Axioms are not provable; they are declared true as part of the basis of the system. You're really still not brushed up on even a second year university level understanding of this stuff. |
| peteolcott <Here@Home>: Apr 27 04:58PM -0500 On 4/27/2019 1:26 PM, Kaz Kylheku wrote: > provable; they are declared true as part of the basis of the system. > You're really still not brushed up on even a second year university > level understanding of this stuff. THESE FOUR AXIOMS PROVIDE THE BASIS FOR COMPLETE CONSISTENT FORMAL SYSTEMS AND NO VALID COUNTER-EXAMPLE CAN BE FORMED TO SHOW OTHERWISE Axiom(0) Stipulates** this definition of Axiom: Expressions of language defined to have the semantic value of Boolean True. Provides the symbolic logic equivalent of true premises. Stipulating** this specification of True and False: (TRUE ↔ ⊤ ∧ FALSE ↔ ⊥) Axiom(1) ∀F ∈ Formal_System ∀x ∈ Closed_WFF(F) (True(F, x) ↔ (F ⊢ x)) Axiom(2) ∀F ∈ Formal_System ∀x ∈ Closed_WFF(F) (False(F, x) ↔ (F ⊢ ¬x)) Thus stipulating** that consequences are provable from axioms. Stipulating** that formal systems are Boolean: Axiom(3) ∀F ∈ Formal_System ∀x ∈ Closed_WFF(F) (True(F,x) ∨ False(F,x)) Screens out semantically unsound sentences as not belonging to the formal system. Eliminating Undecidability and Incompleteness in Formal Systems https://www.researchgate.net/publication/332427635_Eliminating_Undecidability_and_Incompleteness_in_Formal_Systems -- Copyright 2019 Pete Olcott All rights reserved "Great spirits have always encountered violent opposition from mediocre minds." Albert Einstein |
| peteolcott <Here@Home>: Apr 27 05:13PM -0500 On 4/27/2019 4:56 PM, Ike Naar wrote: > But this is wordplay. > If 'provable' means "can be derived from axioms" then it would seem sensible > to classify the axioms themselves as being provable. No that would form a cyclic directed graph forming an infinite evaluation loop. To prove that an expression of language is an axiom merely requires looking it up on a finite list or matching it to an axiom schema, in other words any infinite set of axioms can be algorithmically compressed into a finite set of schema. Eliminating Undecidability and Incompleteness in Formal Systems https://www.researchgate.net/publication/332427635_Eliminating_Undecidability_and_Incompleteness_in_Formal_Systems -- Copyright 2019 Pete Olcott All rights reserved "Great spirits have always encountered violent opposition from mediocre minds." Albert Einstein |
| peteolcott <Here@Home>: Apr 27 05:28PM -0500 On 4/27/2019 1:26 PM, Kaz Kylheku wrote: > provable; they are declared true as part of the basis of the system. > You're really still not brushed up on even a second year university > level understanding of this stuff. Axioms are merely expressions of language that have been defined to have the semantic value of Boolean true. A sound deductive inference model must have no contradictory axioms. True(X) is Provable(X) from True Premises. False(X) is Provable(¬X) from True Premises. Otherwise Unsound(X). This simple little system refutes Gödel's 1931 Incompleteness Theorem ∃F ∈ Formal_System ∃G ∈ Closed_WFF(F) (G ↔ ((F ⊬ G) ∧ (F ⊬ ¬G))) There is no sentence G of Formal System F that is neither True nor False in F. Its refutation of the Tarski Undefinability Theorem requires the basis of the Tarski Undefinability Proof to be understood: http://liarparadox.org/Tarski_Proof_275_276.pdf The third step of the proof: (3) x ∉ Pr if and only if x ∈ Tr is refuted by this version of Axiom(1) x ∈ Pr ↔ x ∈ Tr -- Copyright 2019 Pete Olcott All rights reserved "Great spirits have always encountered violent opposition from mediocre minds." Albert Einstein |
| peteolcott <Here@Home>: Apr 27 05:44PM -0500 On 4/27/2019 4:52 PM, Paul Rubin wrote: > peteolcott <Here@Home> writes: >> I have spent 22 years and 12,000 hours on this. > http://web.mst.edu/%7Elmhall/WhatToDoWhenTrisectorComes.pdf IT ELIMINATES INCOMPLETENESS AND INCONSISTENCY OF FORMAL SYSTEMS NO VALID COUNTER-EXAMPLE EXISTS SHOWING OTHERWISE I DARE YOU TO FIND ONE All that I do is translate the formal proofs to theorem consequences of symbolic logic to conform to the sound deductive inference model. Axioms are merely expressions of language that have been defined to have the semantic value of Boolean true. I made this much simpler for people that do not know symbolic logic: True(X) is Provable(X) from Axioms. False(X) is Provable(¬X) from Axioms. Otherwise Unsound(X). Here it is in symbolic logic: Axiom(1) ∀F ∈ Formal_System ∀x ∈ Closed_WFF(F) (True(F, x) ↔ (F ⊢ x)) Axiom(2) ∀F ∈ Formal_System ∀x ∈ Closed_WFF(F) (False(F, x) ↔ (F ⊢ ¬x)) Axiom(3) ∀F ∈ Formal_System ∀x ∈ Closed_WFF(F) (True(F,x) ∨ False(F,x)) Eliminating Undecidability and Incompleteness in Formal Systems https://www.researchgate.net/publication/332427635_Eliminating_Undecidability_and_Incompleteness_in_Formal_Systems -- Copyright 2019 Pete Olcott All rights reserved "Great spirits have always encountered violent opposition from mediocre minds." Albert Einstein |
| peteolcott <Here@Home>: Apr 27 05:49PM -0500 On 4/27/2019 4:33 PM, j4n bur53 wrote: > Ever looked up the definition what a proof is? A proof > is a sequence D1, ..., Dn, where Di is either an axiom > or the result of applying an inference rule to some http://liarparadox.org/Provable_Mendelson.pdf > already derived statements. Now take n=1. > Whats wrong with you guys? Prolog people might know provable, other software engineers, not as much, so I gave them this much simpler form: Summing it up: True(X) is Provable(X) from True Premises. False(X) is Provable(¬X) from True Premises. Otherwise Unsound(X). When we define this as an Axiom: Expressions of language defined to have the semantic value of Boolean True. Then we can replace the above "True Premises" with {Axiom}. -- Copyright 2019 Pete Olcott All rights reserved "Great spirits have always encountered violent opposition from mediocre minds." Albert Einstein |
| wyniijj@gmail.com: Apr 26 11:56PM -0700 Bo Persson於 2019年4月27日星期六 UTC+8上午4時01分56秒寫道： > the popularity is low - it can also mean that everyone available is > already hired. High popularity. > Bo Persson I admit the measure I made was flawed. However, it forces me to find a way to re-think C++ in practice. In my country, it's estimated about 30,000 new companies established every year. One thing for sure they would setup a web site, so the basic required skills are normally JavaScript,PHP,HTML,Python,MySQL,... In all cases, the need for C++ is either avoided (E.g. using game engine) or seemed deliberately separated to core minimum (If there were existing codes). |
| Melzzzzz <Melzzzzz@zzzzz.com>: Apr 27 07:23AM > In my country, it's estimated about 30,000 new companies established > every year. One thing for sure they would setup a web site, so the > basic required skills are normally JavaScript,PHP,HTML,Python,MySQL,... That is if all they do is cheap web shop.... -- press any key to continue or any other to quit... U ničemu ja ne uživam kao u svom statusu INVALIDA -- Marko Marin Na divljem zapadu i nije bilo tako puno nasilja, upravo zato jer su svi bili naoruzani. -- Mladen Gogala |
| jacobnavia <jacob@jacob.remcomp.fr>: Apr 27 08:09PM +0200 Le 24/04/2019 à 00:47, Lynn McGuire a écrit : > https://alexgaynor.net/2019/apr/21/modern-c++-wont-save-us/ > Neither will Rust or Swift. > Lynn In that article we have: #include <iostream> #include <string> #include <string_view> int main() { std::string s = "Hellooooooooooooooo "; std::string_view sv = s + "World\n"; std::cout << sv; } It took me a while to find this one. Actually, a list view is created with the result of the expression s + "World" This is a temporary object that will disappear instantly, making a view of a string that doesn't exist any more... What bothers me is that there is no automatic mechanism for avoiding any destruction of a string that has still views into it... The constructor of a view could add the view to a list of views in the string. The destructor of the string would fail if there are still views to it. For instance, maybe other methods wpould be preferable |
| jacobnavia <jacob@jacob.remcomp.fr>: Apr 27 09:59PM +0200 Le 27/04/2019 à 20:09, jacobnavia a écrit : > Actually, a list view Sorry! That should have been: Actually, a string view jacob |
| karhtet@gmail.com: Apr 27 01:28AM -0700 How to write program to find bonus? I'm beginner to learn c++. I have working hours and bonus but i can't write code? How i do? |
| Bonita Montero <Bonita.Montero@gmail.com>: Apr 27 10:31AM +0200 > How to write program to find bonus? > I'm beginner to learn c++. I have working hours and bonus but i can't write code? How i do? How do you define "bonus"? |
| ram@zedat.fu-berlin.de (Stefan Ram): Apr 26 11:49PM >Subject: Re: "Modern C++ Won't Save Us" by alex_gaynor |Our analysis shows that among compiled programming languages |such as C, C++, Java, and Go offers the highest energy |efficiency for all of our tested tasks compared to C#, |vb.net, and Rust. Analyzing Programming Languages' Energy Consumption: An Empirical Study Stefanos Georgiou PCI '17, September 2017, Larrisa, Greece This shows that C++ will literally save the world! |
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