Talk:Formal system

message: I have an image I've made that I hope someone can make use of:
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I've placed it into the public domain.
-- Lion Kimbro
: I've made several attempts to down load it.  Times out every time. Mind letting us in on what it is a picture of? Nahaj 00:40:44, 2005-09-08 (UTC)
"It is not assumed that the metalanguage in which proofs are studied is itself less informal than the usual habits of mathematicians suggest."
: Sorry?  What does this mean?
::I think you could rewrite it as "It is assumed that the metalanguage in which proofs are studied is itself at most as formal as the usual habits of mathematicians suggest."  But it's not clear who assumes this or why this can be assumed.  So I've removed the sentence.  -- Felix Wiemann 15:35, 16 August 2006 (UTC)
thread_title:  An image 

message: I do think this article needs an expert that improves the introduction of this article. This introduction should make more clear that the term formal systems is alos a general term used in logic, mathematics, computer science and linguistics, etc. and in what meanings - Mdd 23:39, 7 August 2007 (UTC)
thread_title:  Attention from an expert on the subject 

message: What Unicode symbol is that, and why should it be used in the article?  — Arthur Rubin  (talk) 22:21, 21 May 2008 (UTC)
replies: text: I agree there's no need for it; TeX can be used if there is a real need for it, and TeX math is much more accessible. — Carl (CBM · talk) 22:23, 21 May 2008 (UTC)
replies: text: I'm sorry Arthur, it just was the closest thing I could find. Thanks for correcting it. Be well, Pontiff Greg Bard (talk) 04:29, 22 May 2008 (UTC)
thread_title:  x02111 

message: "An interpreted formal system can be defined as the ordered quadruple <α,\mathcal{I},\mathcal{D}d,\mathcal{D}>." Shouldn't it be stated what the components of the quadruple represent, such as ", in which α is an alphabet, ..."? From the remainder of the section I could not deduce what kind of entities the components represent and what constraints exist among them.  --Lambiam 17:15, 23 May 2008 (UTC)
replies: text: You are correct. I have inserted the definitions. Sorry it took so long. Pontiff Greg Bard (talk) 22:57, 25 May 2008 (UTC)
thread_title:  Ordered quadruple 

message: "A formal language is a set A of strings (finite sequences) on a fixed alphabet α. While a formal language can be thought of as identical to its set of well-formed formula, a formal system cannot be thought of as identical with its set of theorems. Two different formal systems may produce the same set of theorems."
The problem with this is that it creates the impression that the set of theorems is not a formal language.  Which it clearly is.  Taemyr (talk) 14:12, 18 September 2009 (UTC)
thread_title:  From formal language 

message: There's no universally agreed way to define a logical system. There's even an entire book devoted to the topic, which I've added to the further reading section. It should be a rich resource for this article, much better than the Dictionary of philosophy. Pcap ping 05:48, 19 September 2009 (UTC)
thread_title:  Added further reading 

message: There have been added several tags, including pov title, and accuracy. I am pretty sure the title was already discussed a long time ago, and a consensus was reached on "formal system." I am not sure exactly what accuracy issues are being considered.
Untag -- no sufficient cause to move titles, no accuracy issues identified Pontiff Greg Bard (talk) 18:22, 20 October 2009 (UTC)
replies: text: Excuse me? Are you not capable of working with others? You have still failed to respond to the request for an actual claim in the article which is disputed or inaccurate. If you do not provide one, then you are demonstrating that you are not a good faith editor. You have to make it possible for civil discussion about content. Otherwise you are being a troll. This is uncalled for and the tags will be removed if there is no case made by yourself for them. Don't try to avoid the issue by attacking me either. You are on notice. Pontiff Greg Bard (talk) 05:04, 8 November 2009 (UTC)
replies: text: No, I am one of many editors with whom GregBard cannot work, as the discussion above makes clear. This is the imposition of an arbitrary POV by a single editor; I do not now have the time or expertise to get this right - my field is algebra; but it is clearly wrong.  Septentrionalis PMAnderson 14:26, 8 November 2009 (UTC)

text: You have still failed to actually tell us what your problem with the article is. However you have managed to identify yourself as a trouble maker. At any point you decide to grow up and engage in civil discourse, I will join you. Pontiff Greg Bard (talk) 05:22, 9 November 2009 (UTC)
replies: text: See also Charles matthew's comments, two sections down. Septentrionalis PMAnderson 23:38, 9 November 2009 (UTC)
thread_title:  Tags 

message: * In this edit a section is copy/paste from the Formal language article, and an other section from the Formal grammar article. -- Mdd (talk) 12:00, 29 October 2009 (UTC)
thread_title:  Copy-paste registration 

message: Whatever the definitional and terminological level gets resolved to, it seems clear that this article fails to explain the role of formal systems. There is a throw-away remark about "formalism". Formalization redirects to the page, but is not seriously discussed (why no mention of the immense efforts to formalize theories? - both applications and history seem to have gone missing). Charles Matthews (talk) 17:15, 8 November 2009 (UTC)
replies: text: These are all wonderful and legitimate concerns. However, they do not really justify Pmandersons' tags or attitude (he has appealed to your note here for justifying his actions). Suffice it to say the the article could use some expansion. However, I still don't see any POV issues here at all. I will work on it soon, and consider your input. Be well. Pontiff Greg Bard (talk) 00:26, 10 November 2009 (UTC)
replies: text: Of course you don't; it's your POV. (And please stop working on this article; you've done enough harm already.) Septentrionalis PMAnderson 03:32, 10 November 2009 (UTC)

text: Um yeah, you go ahead and quit editing Wikipedia entirely since you can't be civil. Not going to? Gee I guess we both wasted our time releasing our annoyed bowels. No body cares how annoyed you are PM. It's your own choice. Grow up. Pontiff Greg Bard (talk) 03:56, 10 November 2009 (UTC)
thread_title: Moving ahead

message: I've never seen this definition of a "logic" before. In my experience, corroborated by the SEP article "Modal logic", a logic is a language (set of formulae) with an associated set of inference rules; i.e., it's purely formal and the semantics are optional. QVVERTYVS (hm?) 14:47, 4 June 2015 (UTC)
replies: text: I agree, changed. Mathnerd314159 (talk) 16:22, 9 August 2022 (UTC)
thread_title:  No semantics needed 

message: The lead paragraph currently mentions Spinoza and their work being based on Euclid, but does not mention how either of them relate to formal systems. There is no mention of them in the rest of the article, so should it just be removed or reworded with an expanded explanation later in the article?
I don't know enough about the subject to do this myself (other than to remove it completely). Spike 'em (talk) 10:24, 14 September 2018 (UTC)
thread_title:  Confusing lead section 

message: I am uneasy with the following: 
Formal proofs are sequences of well-formed formulas (or wff for short). For a wff to qualify as part of a proof, it might either be an axiom or be the product of applying an inference rule on previous wffs in the proof sequence. The last wff in the sequence is recognized as a theorem.
With a refutation proof system (like for example a resolution method), the last sentence of a proof is the unsatisfiable sentence (ther empoty clause with resolution). With a refutation proof system, the sentence proven is not the last of the proof but instead constructable from one premise or several premises. 
Furthermore, I do not quite see the need to refer to well-formed formulas. It is all about sentences (closed formulas or, if in a context like parsing where illegal expressions must be considered, closed well-formed formulas. Is there a need in explaining what is a proof system to consider expressions that are not well-formed? 
Bbbaat (talk) 19:31, 27 March 2019 (UTC)
thread_title:  Proof system  

message: The term "deductive system" as defined in this article doesn't seem to be exactly the same as defined in a section of the article on first-order logic (that, by the way, seems much more mature). On the other hand, it seems to be related to the notion of Proof system (cf. my comment on the talk page there).
Leonry (talk) 19:01, 25 October 2020 (UTC)
thread_title:  Deductive systems