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What I see happening in this discussion is that a user was affronted personally and began, as a normal human response, to rationalize his positions, inventing or gathering arguments that are weak, and continuing to make assumptions about the topic and about what others were writing, that are not shared.
 
What I see happening in this discussion is that a user was affronted personally and began, as a normal human response, to rationalize his positions, inventing or gathering arguments that are weak, and continuing to make assumptions about the topic and about what others were writing, that are not shared.
  
When we are offended, in general, our thinking goes awry, being dominated by survival reactions, and this is all stuff that I spent years studying and in training over. Pointing this out does not make any position "right" or "wrong," which are judgments, not actually facts. To move beyond this requires some caution and care. To really understand this may require reading the entire thread, which was not about persons, originally, but about Sudoku and a particular claimed uniqueness pattern. It became increasingly rude.
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When we are offended, in general, our thinking goes awry, being dominated by survival reactions, and this is all stuff that I spent years studying and in training over. It is very human to do this, but it can create intractable disputes.
  
This turned into a replay of common arguments about uniqueness, I've seen in many places. See the page supra.
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Pointing this out does not make any position "right" or "wrong," which are judgments, not actually facts. To move beyond this requires some caution and care. To really understand this may require reading the entire thread, which was not about persons, originally, but about Sudoku and a particular claimed uniqueness pattern. It became increasingly rude.
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This also became a replay of common arguments about uniqueness, I've seen in many places. See the page supra.
  
 
[https://www.reddit.com/r/sudoku/comments/eo57ww/interesting_uniqueness_pattern/ Interesting uniqueness pattern comment reply]
 
[https://www.reddit.com/r/sudoku/comments/eo57ww/interesting_uniqueness_pattern/ Interesting uniqueness pattern comment reply]
  
from [https://www.reddit.com/user/sotolf2 sotolf2] via [ /r/sudoku] [https://www.reddit.com/r/sudoku/comments/eo57ww/interesting_uniqueness_pattern/fegvxby/ Jan 15 2020 15:55 GMT] - quorting u/Abdlomax (Abd on this wiki) Abd's original comment is in indented. Responses here should be at least double-indented, in bold italic, and signed (with <nowiki>~~~~</nowiki>) and may be refactored for clarity.
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from [https://www.reddit.com/user/sotolf2 sotolf2] via /r/sudoku  [https://www.reddit.com/r/sudoku/comments/eo57ww/interesting_uniqueness_pattern/fegvxby/ Jan 15 2020 15:55 GMT] - quoting u/Abdlomax (Abd on this wiki) Abd's original comment is in indented italic. Responses here should be further indented, in bold italic, and signed (with <nowiki>~~~~</nowiki>) and may be refactored for clarity. --[[User:Abd|Abd]] ([[User talk:Abd|talk]]) 21:50, 15 January 2020 (UTC)
 
----
 
----
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==Definition of sudoku==
 
:''Who said that uniqueness is "invalid"? Certainly not me! Rather, uniqueness is based on an assumption that was not stated when Sudoku were first formally defined and published. It was still assumed, by both authors and solvers. Some books add it as an afterthought.''
 
:''Who said that uniqueness is "invalid"? Certainly not me! Rather, uniqueness is based on an assumption that was not stated when Sudoku were first formally defined and published. It was still assumed, by both authors and solvers. Some books add it as an afterthought.''
  
 
So where is this authorative definition? I certainly haven't seen it anywhere, and I don't really belive one exists, if we are going to treat sudoku as a logic puzzle though it will have to have a logically deducable solution, something that is not possible if there are multiple solutions.
 
So where is this authorative definition? I certainly haven't seen it anywhere, and I don't really belive one exists, if we are going to treat sudoku as a logic puzzle though it will have to have a logically deducable solution, something that is not possible if there are multiple solutions.
 
::'''''What is published is a picture of a puzzle with
 
::'''''What is published is a picture of a puzzle with
:::You must place digits into the grid in such a way that every row, every column, and every 3x3 box contains each of the digits 1 through 9
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:::'''You must place digits into the grid in such a way that every row, every column, and every 3x3 box contains each of the digits 1 through 9'''
 
::'''''This, or something very similar, is in every book on sudoku I have, which is many. As well, there are dictionary definitions. I'll link to [https://www.merriam-webster.com/dictionary/sudoku Merriam-Webster]. Given that there is no contrary definition shown, I'd call that "authoritative."
 
::'''''This, or something very similar, is in every book on sudoku I have, which is many. As well, there are dictionary definitions. I'll link to [https://www.merriam-webster.com/dictionary/sudoku Merriam-Webster]. Given that there is no contrary definition shown, I'd call that "authoritative."
  
::'''''As well, the definitions claim nothing about logic or "logic puzzle". Rather, "solvable with logic" is a claim made ''about'' Sudoku, and SW Solver uses computer logic to crack any Sudoku, including multiple-solution Sodoku, reporting all solutions up to 500.  
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::'''''As well, the definitions claim nothing about logic or "logic puzzle". Rather, "solvable with logic" is a claim made ''about'' Sudoku, and SW Solver uses computer logic to crack any Sudoku, including multiple-solution Sodoku, reporting all solutions up to 500. --[[User:Abd|Abd]] ([[User talk:Abd|talk]]) 21:50, 15 January 2020 (UTC)
 
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==Is sudoku solving logic?==
 
:''Can we agree that sudoku solving is logic?''
 
:''Can we agree that sudoku solving is logic?''
  
 
Not if a puzzle has multiple solutions, if it does it will be logically unsolveable.
 
Not if a puzzle has multiple solutions, if it does it will be logically unsolveable.
::'''''Counterexample given.'''''
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::'''''Counterexample given.''''' --[[User:Abd|Abd]] ([[User talk:Abd|talk]]) 21:50, 15 January 2020 (UTC)
 
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==Any answer that satisfies the rules is "valid."==
 
:''Any answer that satisfies the rules of of sudoku is "valid," so it is a solution. Claiming that guessing is required is not clear thinking.''
 
:''Any answer that satisfies the rules of of sudoku is "valid," so it is a solution. Claiming that guessing is required is not clear thinking.''
  
 
I don't think I did, I might have though, but you can't logically deduce a solution if there are two valid solutions, unless you have some extra rules.
 
I don't think I did, I might have though, but you can't logically deduce a solution if there are two valid solutions, unless you have some extra rules.
::'''''When we become personally involved in a dispute, defending ourselves, we become very concerned about what we said and did not say. What I wrote was clear and the user does not deny it, but then repeats his claim about what "can't be done," when it clearly can be done, is obviously done with SW Solver, and has been personally done by me, as I have reported. Underneath that is an assumption that solving a sodoku is finding one answer, and that if there is more than one, one must guess which it is, when if there is more than one, any answer still satisfied the problem presented by the puzzle. Finding "the answer" ''assumes'' only one.
 
  
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::'''''When we become personally involved in a dispute, defending ourselves, we become very concerned about what we said and did not say. What I wrote was clear and the user does not deny it, but then repeats his claim about what "can't be done," when it clearly can be done, is obviously done with SW Solver, and has been personally done by me, as I have reported. Underneath that is an assumption that solving a sodoku is finding one answer, and that if there is more than one, one must guess which it is, when if there is more than one, any answer still satisfied the problem presented by the puzzle. Finding "the answer" ''assumes'' only one. --[[User:Abd|Abd]] ([[User talk:Abd|talk]]) 21:50, 15 January 2020 (UTC)
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=="unsolvable without guessing==
 
:''But then difficult puzzles began to be developed, considered "unsolvable without guessing." (And the language there was way cuckoo.)''
 
:''But then difficult puzzles began to be developed, considered "unsolvable without guessing." (And the language there was way cuckoo.)''
  
 
I 100% agree with you in that.
 
I 100% agree with you in that.
  
::'''''Great! Let's build on that.
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::'''''Great! Let's build on that. --[[User:Abd|Abd]] ([[User talk:Abd|talk]]) 21:50, 15 January 2020 (UTC)
 
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==straw man argument==
 
:''Sotolf2, you are creating a straw man argument, that someone claimed uniqueness is "invalid," when what is being said is that uniqueness is based on an additional assumption, not formally stated originally.''
 
:''Sotolf2, you are creating a straw man argument, that someone claimed uniqueness is "invalid," when what is being said is that uniqueness is based on an additional assumption, not formally stated originally.''
  
 
Again, until this "original" document of sudoku holiness is somewhere I can access it and see it I might agree with you, but I will assume that a sudoku puzzle should be logically deducible, or it is no longer a logic puzzle.
 
Again, until this "original" document of sudoku holiness is somewhere I can access it and see it I might agree with you, but I will assume that a sudoku puzzle should be logically deducible, or it is no longer a logic puzzle.
  
::'''''Becoming sarcastic, another relatively objective sign of attachment. I suggest looking at ''any Sudoku book or any dictionary.'' I've pointed out that unique-answer was an unstated assumption, an intention. But in this world, we do not always realize our intentions, and a puzzle created which has more than one solution is called "improper." Not "not a Sudoku." And these are solvable, that is, on can find numbers to fill in that satisfy the constraints. "Should be" is all personal judgment. And single-solution is not a requirement for logic puzzles. Again, it is normally intended. Math is a kind of logic. What is the square root of four? Find an answer and prove it.
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::'''''Becoming sarcastic, another relatively objective sign of attachment. I suggest looking at ''any Sudoku book or any dictionary.'' I've pointed out that unique-answer was an unstated assumption, an intention. But in this world, we do not always realize our intentions, and a puzzle created which has more than one solution is called "improper." Not "not a Sudoku." And these are solvable, that is, on can find numbers to fill in that satisfy the constraints. "Should be" is all personal judgment. And single-solution is not a requirement for logic puzzles. Again, it is normally intended. Math is a kind of logic. What is the square root of four? Find an answer and prove it. --[[User:Abd|Abd]] ([[User talk:Abd|talk]]) 21:50, 15 January 2020 (UTC)
 
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==An assumption of uniqueness proven invalid==
 
:''What I did, among other things, was to prove that the assumption of uniqueness was invalid for this puzzle. That is most clearly accomplished by showing at least two.''
 
:''What I did, among other things, was to prove that the assumption of uniqueness was invalid for this puzzle. That is most clearly accomplished by showing at least two.''
  
 
This is what I personally classify as a bad puzzle, just as we would classify "10 They dog ago go buy days" as a bad English sentence even though it's kind of understandable it's still not a good sentence.
 
This is what I personally classify as a bad puzzle, just as we would classify "10 They dog ago go buy days" as a bad English sentence even though it's kind of understandable it's still not a good sentence.
  
::'''''I find such puzzles interesting, and "bad" is a personal reaction, not a fact. Because "proper Sudoku" is objectively defined, we can agree that such a puzzle is improper. I happen to like some kinds of impropriety, in general. It's a personal choice; in general I recommend noticing such reactions -- which is what that is -- and digging up the roots and looking at them, because there can be found much that disempowers us. It is not therefore "bad" or "wrong," but the disempowerment can be very real.
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::'''''I find such puzzles interesting, and "bad" is a personal reaction, not a fact. Because "proper Sudoku" is objectively defined, we can agree that such a puzzle is improper. I happen to like some kinds of impropriety, in general. It's a personal choice; in general I recommend noticing such reactions -- which is what that is -- and digging up the roots and looking at them, because there can be found much that disempowers us. It is not therefore "bad" or "wrong," but the disempowerment can be very real. --[[User:Abd|Abd]] ([[User talk:Abd|talk]]) 21:50, 15 January 2020 (UTC)
  
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==u/the_gr8_n8 is solid==
 
:''u/the_gr8_n8 is solid here''
 
:''u/the_gr8_n8 is solid here''
  
 
How so, he's assuming some kind of "Ground rules" that he still denies to supply. Also he's using rude language for no reason at all.
 
How so, he's assuming some kind of "Ground rules" that he still denies to supply. Also he's using rude language for no reason at all.
::'''''He was assuming nothing more than what I've shown above. You were asking him to supply what everyone knows, from his point of view. As to "rude language," the first rude language here was not from him. Using "hate" about an inanimate object is not "rude." It's rather ordinary speech. And he has not "denied to supply." That someone does not answer immediately is meaningless. It was not a refusal. But when we become attached, it all seems like an emergency that we must confront.
 
  
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::'''''He was assuming nothing more than what I've shown above. You were asking him to supply what everyone knows, from his point of view. As to "rude language," the first rude language here was not from him. Using "hate" about an inanimate object is not "rude." It's rather ordinary speech. And he has not "denied to supply." That someone does not answer immediately is meaningless. It was not a refusal. But when we become attached, it all seems like an emergency that we must confront. --[[User:Abd|Abd]] ([[User talk:Abd|talk]]) 21:50, 15 January 2020 (UTC)
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==what does "I hate" mean?==
 
:''Saying that I "hate" something is not a claim that it's wrong or bad or defective by some objective standard. It's simply how I feel''
 
:''Saying that I "hate" something is not a claim that it's wrong or bad or defective by some objective standard. It's simply how I feel''
  
 
"Saying that I hate muslims is not Saying that I "hate" something is not a claim that it's wrong or bad or defective by some objective standard. It's simply how I feel"
 
"Saying that I hate muslims is not Saying that I "hate" something is not a claim that it's wrong or bad or defective by some objective standard. It's simply how I feel"
  
::'''''Using an analogy like that is more evidence of attachment, setting aside the incoherence, which becomes common when we are attached.  
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::'''''Using an analogy like that is more evidence of attachment, setting aside the incoherence, which becomes common when we are attached. --[[User:Abd|Abd]] ([[User talk:Abd|talk]]) 21:50, 15 January 2020 (UTC)
  
 
Phrased like that don't you see that this doesn't really hold water?
 
Phrased like that don't you see that this doesn't really hold water?
  
::'''''No, I don't, the opposite. Equating "I hate [ethnic group]" is socially quite rude, even if true, and if true it is creating a social problem, because a group might decide to exclude "haters." But saying "I hate [object]" is simply an expression of a personal reaction. It was not rude, at all. It implies intensity, but is commonly used even without that. It simply means "I don't like it." As I wrote:
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::'''''No, I don't, the opposite. Equating "I hate [ethnic group]" is socially quite rude, even if true, and if true it is creating a social problem, because a group might decide to exclude "haters." But saying "I hate [object]" is simply an expression of a personal reaction. It was not rude, at all. It implies intensity, but is commonly used even without that. It simply means "I don't like it." As I wrote next.  --[[User:Abd|Abd]] ([[User talk:Abd|talk]]) 21:50, 15 January 2020 (UTC)
 
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==hatred in ordinary speech can be just a feeling, not rude==
 
:''Obviously, that "hatred" is weak, just a feeling that arises. I am also eager to get the candidate lists done, making them complete, and, overall, pleasure at that dominates.''
 
:''Obviously, that "hatred" is weak, just a feeling that arises. I am also eager to get the candidate lists done, making them complete, and, overall, pleasure at that dominates.''
  
 
Dislike and hate is not the same.
 
Dislike and hate is not the same.
::'''''Again, the user is assuming that he has the authority to define the meaning of language. They are the same from some points of view, and different from others, which is like just about everything. In fact, "I dislike Muslims" could be almost as rude as "I hate Muslims." Depends on context. All Muslims? And all usages of uniqueness strategies?
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::'''''Again, the user is assuming that he has the authority to define the meaning of language. They are the same from some points of view, and different from others, which is like just about everything. In fact, "I dislike Muslims" could be almost as rude as "I hate Muslims." Depends on context. All Muslims? And all usages of uniqueness strategies? --[[User:Abd|Abd]] ([[User talk:Abd|talk]]) 21:50, 15 January 2020 (UTC)
 
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==assumption of possible solution==
 
:''Yes, that a sudoku has any solution is also "up in the air," meaning unproven until the solution has been demonstrated by logic from the basics. Yet I and everyone else makes that assumption, because no-solution puzzles are even rarer than multiple-solution ones.''
 
:''Yes, that a sudoku has any solution is also "up in the air," meaning unproven until the solution has been demonstrated by logic from the basics. Yet I and everyone else makes that assumption, because no-solution puzzles are even rarer than multiple-solution ones.''
  
 
Yeah, so why is it okay to assume that the puzzle has any solutions but not that it has a single one?
 
Yeah, so why is it okay to assume that the puzzle has any solutions but not that it has a single one?
  
::'''''Again we see the usage of undefined terms, not used by others, as if it what they believe. "Okay." What does that mean? And who has claimed that it is "not okay" to use the assumption of single solution? Nobody said that!  
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::'''''Again we see the usage of undefined terms, not used by others, as if it what they believe. "Okay." What does that mean? And who has claimed that it is "not okay" to use the assumption of single solution? Nobody said that! --[[User:Abd|Abd]] ([[User talk:Abd|talk]]) 21:50, 15 January 2020 (UTC)
 
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==speed not Abd's goal==
 
:''Because speed is not my goal (at all), I prefer to use uniqueness but not to depend on it. That's a preference, not some critique of uniqueness.''
 
:''Because speed is not my goal (at all), I prefer to use uniqueness but not to depend on it. That's a preference, not some critique of uniqueness.''
  
 
Yeah, I see nothing wrong about that at all, we all have preferences likes and dislikes, what I have a problem with is to claim others make "no good" assumptions, when it's a neccessity for what we all enjoy in a puzzle, that it's logically solvable.
 
Yeah, I see nothing wrong about that at all, we all have preferences likes and dislikes, what I have a problem with is to claim others make "no good" assumptions, when it's a neccessity for what we all enjoy in a puzzle, that it's logically solvable.
  
::'''''Again, if someone made that claim, it wasn't me. "no good" was in quotes. Okay, who said it? Again, the user is also assuming that his experience is universal. All sudoku are logically solvable, so claiming the "necessity" of what is ''inevitable'' is odd. Again, the assumption underneath this is that unique-solution is necessary for enjoyment, when what we enjoy is about us, not about the puzzles. I enjoy all sudoku, except I've never tried to create them (which is more or less what the blank puzzle argument is about. I did, at one point, attempt to determine the error that made a puzzle multiple-solution. That was fun, so it stands as a counterargument to the "necessity" argument. (With a BUG puzzle, any of the BUG cells becoming a Given fixes the problem.)
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::'''''Again, if someone made that claim, it wasn't me. "no good" was in quotes. Okay, who said it? Again, the user is also assuming that his experience is universal. All sudoku are logically solvable, so claiming the "necessity" of what is ''inevitable'' is odd. Again, the assumption underneath this is that unique-solution is necessary for enjoyment, when what we enjoy is about us, not about the puzzles. I enjoy all sudoku, except I've never tried to create them (which is more or less what the blank puzzle argument is about. I did, at one point, attempt to determine the error that made a puzzle multiple-solution. That was fun, so it stands as a counterargument to the "necessity" argument. (With a BUG puzzle, any of the BUG cells becoming a Given fixes the problem.) --[[User:Abd|Abd]] ([[User talk:Abd|talk]]) 21:50, 15 January 2020 (UTC)
 
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==pointing to uniqueness as-it-is interpreted as if hatred==
 
:''It has happened here a number of times that if I pointed out that using uniqueness as if proof.''
 
:''It has happened here a number of times that if I pointed out that using uniqueness as if proof.''
  
::'''''A fuller quote is needed here:
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::'''''A fuller quote is needed here.
 
:::<small>It has happened here a number of times that if I pointed out that using uniqueness as if proof was relying on argument from authority, and that was assumed to be "bad," and that therefore I "hated" uniqueness, all of which was straw man. It would be totally silly to hate routine reality! It is also routine reality that people make assumptions about what others mean, that are not necessarily valid. Argument from authority is considered a logical error, and errors are bad, right? Again, notice the reactive thinking. "Trial and error" is "bad," because it is "guessing" and both "guessing" and "error" are "bad."</small>
 
:::<small>It has happened here a number of times that if I pointed out that using uniqueness as if proof was relying on argument from authority, and that was assumed to be "bad," and that therefore I "hated" uniqueness, all of which was straw man. It would be totally silly to hate routine reality! It is also routine reality that people make assumptions about what others mean, that are not necessarily valid. Argument from authority is considered a logical error, and errors are bad, right? Again, notice the reactive thinking. "Trial and error" is "bad," because it is "guessing" and both "guessing" and "error" are "bad."</small>
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::'''''The user actually agrees, though we have no definition of "valid." --[[User:Abd|Abd]] ([[User talk:Abd|talk]]) 21:50, 15 January 2020 (UTC)
  
 
I can agree that it will be wrong to use it as a proof, as it isn't really, as a shortcut to solving, like colouring or fishes or anything I don't see how it's any less valid than anything else.
 
I can agree that it will be wrong to use it as a proof, as it isn't really, as a shortcut to solving, like colouring or fishes or anything I don't see how it's any less valid than anything else.
  
::'''''Nobody has claimed that it is not "valid." Rather it has been claimed that it is a form of argument from authority, specifically from authority that is quite reliable, but not infallible. To use it or not is a personal choice. It is only "invalid" as a logical proof, but it is totally valid (i.e, completely reasonable) as a heuristic. What I've been promoting is an awareness of the difference, and of the (very small) risk, that using a uniqueness strategy can cover up the existence of additional answers or, even more rarely, break a puzzle.
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::'''''Nobody has claimed that it is not "valid." Rather it has been claimed that it is a form of argument from authority, specifically from authority that is quite reliable, but not infallible. To use it or not is a personal choice. It is only "invalid" as a logical proof, but it is totally valid (i.e, completely reasonable) as a heuristic. What I've been promoting is an awareness of the difference, and of the (very small) risk, that using a uniqueness strategy can cover up the existence of additional answers or, even more rarely, break a puzzle. --[[User:Abd|Abd]] ([[User talk:Abd|talk]]) 21:50, 15 January 2020 (UTC)
 
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==meaning of argument from authority==
 
:''argument from authority''
 
:''argument from authority''
  
 
An arguement from authority would be to claim that someone makes an assumption based on something like someone said, like "It's not part of the original definition of sudoku" And I'm not the one claiming that.
 
An arguement from authority would be to claim that someone makes an assumption based on something like someone said, like "It's not part of the original definition of sudoku" And I'm not the one claiming that.
  
::'''''This is incoherent, but does it matter? Authority is here being confused with verifiable reality. The "original definition" was actually example, published puzzles with rules, and they all agree. The dictionary definitions follow that and the obvious. All that was said was that uniqueness was not part of the original definition, which it wasn't. Yes, the other user and I claimed that, and it's verifiable and no counter-example has been asserted. It's just fact. And it is also fact -- apparently -- that it was routinely assumed that published puzzles would have only one solution. But that was an assumption based on intention, not a fact, though supported by widespread experience that all puzzles -- in one person's experience -- have only one solution. What's the reality here? I don't think there is an real disagreement about it, but only over a pile of "shoulds" and "likes" and "better thans."
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::'''''This is incoherent, but does it matter? Authority is here being confused with verifiable reality. The "original definition" was actually example, published puzzles with rules, and they all agree. The dictionary definitions follow that and the obvious. All that was said was that uniqueness was not part of the original definition, which it wasn't. Yes, the other user and I claimed that, and it's verifiable and no counter-example has been asserted. It's just fact. And it is also fact -- apparently -- that it was routinely assumed that published puzzles would have only one solution. But that was an assumption based on intention, not a fact, though supported by widespread experience that all puzzles -- in one person's experience -- have only one solution. What's the reality here? I don't think there is an real disagreement about it, but only over a pile of "shoulds" and "likes" and "better thans." --[[User:Abd|Abd]] ([[User talk:Abd|talk]]) 21:50, 15 January 2020 (UTC)
  
 
For me guessing would be to go with something before you have a convincing reason to go for it, which I don't think colouring is, colouring is not guessing, and neither is uniqueness. Not that I think guessing would not be a valid way to get to a solution, it's just not one that I like to use myself.
 
For me guessing would be to go with something before you have a convincing reason to go for it, which I don't think colouring is, colouring is not guessing, and neither is uniqueness. Not that I think guessing would not be a valid way to get to a solution, it's just not one that I like to use myself.
::'''''Uniqueness is not guessing in itself. It is noticing a pattern that, if the solution requires it, would have more than one solution, and then using that pattern to solve the puzzle is "guessing" that the puzzle is not an exception. But a guess that can be expected to be "correct" almost all the time is not what we would ordinarily call guessing. It is relying on what is common and normal, with exceptions being quite rare. Simply not a proof.  
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::'''''Uniqueness is not guessing in itself. It is noticing a pattern that, if the solution requires it, would have more than one solution, and then using that pattern to solve the puzzle is "guessing" that the puzzle is not an exception. But a guess that can be expected to be "correct," almost all the time, is not what we would ordinarily call guessing. It is inference from what is common and normal, with exceptions being quite rare. Simply not a ''proof''. --[[User:Abd|Abd]] ([[User talk:Abd|talk]]) 21:52, 15 January 2020 (UTC)
  
 
I just get annoyed when someone claims I make assumptions that "Are not valid" and they themselves aren't able to make at least some reasoning without acting out and being rude like was the case here.
 
I just get annoyed when someone claims I make assumptions that "Are not valid" and they themselves aren't able to make at least some reasoning without acting out and being rude like was the case here.
  
::'''''Right. And I get annoyed when someone asserts I claimed something I did not claim. First question, for me, is "did I claim that?" If so, I'll write "Damn straight!" And if not, I'll object. Or not. Depends on the effect I expect. The claims that I "hated uniqueness" I considered potentially damaging, so I confronted them. But the other user here was really just saying "I hate to use uniqueness," which is ordinary speech and not offensive, and I pointed out that it could be disempowering, because noticing a uniqueness strategy can be useful. Just not a proof! So if we want proof, we won't rely on it, we will use direct logic, without the assumption.
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::'''''Right. And I get annoyed when someone asserts I claimed something I did not claim, or does this about someone else. First question, for me, is "was this claimed?" If so, I'll write "Damn straight!" And if not, I'll object. Or not. Depends on the effect I expect. The claims that I "hated uniqueness" I considered potentially damaging, so I confronted them. But the other user here was really just saying "I hate to use uniqueness," which is ordinary speech and not offensive, and I pointed out that it could be disempowering, because noticing a uniqueness strategy can be useful. Just not a proof! So if we want proof, we won't rely on it, we will use direct logic, without the assumption.
 
::'''''But if we just want to get the freaking answer, and don't care about proving uniqueness, we'll use it.
 
::'''''But if we just want to get the freaking answer, and don't care about proving uniqueness, we'll use it.
 
::'''''Neither of these approaches are "valid" or "invalid." They are choices and, as such, they are useful or not. I happen to enjoy doing sudoku, and requiring proof of uniqueness requires that I do more sudoku logic. I happen to consider that fun. So I do wonder about people that avoid it, but don't question for a moment their right to make the choice.  
 
::'''''Neither of these approaches are "valid" or "invalid." They are choices and, as such, they are useful or not. I happen to enjoy doing sudoku, and requiring proof of uniqueness requires that I do more sudoku logic. I happen to consider that fun. So I do wonder about people that avoid it, but don't question for a moment their right to make the choice.  
 
::'''''I ask the question here: if it is only a little more process -- or not even much more at all -- to prove uniqueness rather than assume it, what will you choose?
 
::'''''I ask the question here: if it is only a little more process -- or not even much more at all -- to prove uniqueness rather than assume it, what will you choose?
::'''''I do not propose that either choice is wrong. It is like choosing a seed pair for SBN. There is no wrong choice. There are choices that require more patience than others, and patience is a fantastic thing to develop, but when and where to do that is all about personal choice, not "right" and "wrong."  
+
::'''''I do not propose that either choice is wrong or "invalid." It is like choosing a seed pair for SBN. There is no wrong choice. There are choices that require more patience than others, and patience is a fantastic thing to develop, but when and where to do that is all about personal choice, not "right" and "wrong." --[[User:Abd|Abd]] ([[User talk:Abd|talk]]) 21:50, 15 January 2020 (UTC)
  
 +
==suggested syllogisms==
 
So I suggest the syllogisms
 
So I suggest the syllogisms
 
+
===First===
 
*A: Sudoku is a logical puzzle
 
*A: Sudoku is a logical puzzle
::'''''That is a description of process we have developed to solve sudoku, not of sudoku themselves. Sudoku are patterns of numbers in a grid, with blanks, and a suggestion to fill in the blanks with more numbers to solve it, satisfying the rules. How we do that is not stated. We could guess, and if we find a solution that way -- pure guessing is damned inefficient! -- it would still be a solution if it satisfies the rules.
+
::'''''That is a description of process we have developed to solve sudoku, not of sudoku themselves. Sudoku are patterns of numbers in a grid, with blanks, and a suggestion to fill in the blanks with more numbers to solve it, satisfying the rules. How we do that is not stated. We could guess, and if we find a solution that way -- pure guessing is damned inefficient! -- it would still be a solution if it satisfies the rules. --[[User:Abd|Abd]] ([[User talk:Abd|talk]]) 21:50, 15 January 2020 (UTC)
 
*B: All logical puzzle has to be solvable by logic.
 
*B: All logical puzzle has to be solvable by logic.
::'''''That assumes the conclusion. We make that assumption, it also was not stated. A puzzle may come to us that has no solution. They are rare, but they exist. They are still puzzles, and they are still "solvable by logic" in the sense that logic can prove that there is no solution.
+
::'''''That assumes the conclusion. We make that assumption, it also was not stated. A puzzle may come to us that has no solution. They are rare, but they exist. They are still puzzles, and they are still "solvable by logic" in the sense that logic can prove that there is no solution. --[[User:Abd|Abd]] ([[User talk:Abd|talk]]) 21:50, 15 January 2020 (UTC)
 
*C: Sudoku has to be solveable by logic
 
*C: Sudoku has to be solveable by logic
::'''''Conclusion created by assumptions. In fact, with a reasonable definition of "solveable," all sudoku are solvable. There might be a very large number of possible solutions.  
+
::'''''Conclusion created by assumptions. In fact, with a reasonable definition of "solveable," all sudoku are solvable. There might be a very large number of possible solutions. --[[User:Abd|Abd]] ([[User talk:Abd|talk]]) 21:50, 15 January 2020 (UTC)
 
+
===Second===
 
*A: Sudoku has to be solveable by logic
 
*A: Sudoku has to be solveable by logic
::'''''garbage in, garbage out. "Has to be" is undefined. It is the language of compulsion and assumptions about what must be or else . . . or else what? Given that all sudoku are solvable by logic, this is meaningless.
+
::'''''garbage in, garbage out. "Has to be" is undefined. It is the language of compulsion and assumptions about what must be or else . . . or else what? Given that all sudoku are solvable by logic, this is meaningless. --[[User:Abd|Abd]] ([[User talk:Abd|talk]]) 21:50, 15 January 2020 (UTC)
 
*B: A puzzle with multiple solutions aren't solveable by logic
 
*B: A puzzle with multiple solutions aren't solveable by logic
::'''''This assumes single solution in "solvable." But if a puzzle has two and only two solutions, logic can find both of them. Either one is a solution, satisfying the rules, and showing both completely solves the puzzle, no questions.  
+
::'''''This assumes single solution in "solvable." But if a puzzle has two and only two solutions, logic can find both of them. Either one is a solution, satisfying the rules, and showing both completely solves the puzzle, no questions. --[[User:Abd|Abd]] ([[User talk:Abd|talk]]) 21:50, 15 January 2020 (UTC)
 
*C: Sudoku with multiple solutions are not valid
 
*C: Sudoku with multiple solutions are not valid
::'''''"Not valid" is undefined. The term "improper:" was developed to describe Sudoku with no solution or with multiple solutions.  
+
::'''''"Not valid" is undefined. The term "improper:" was developed to describe Sudoku with no solution or with multiple solutions. --[[User:Abd|Abd]] ([[User talk:Abd|talk]]) 21:50, 15 January 2020 (UTC)
 
+
===Third===
 
*A: A valid sudoku has one solution
 
*A: A valid sudoku has one solution
::'''''This is the problem with complex chains of logic. Any defect breaks it. The term is not "valid," it is "proper." That is correct, a "proper sudoku" has one solution. By definition, not by some conclusory logic.
+
::'''''This is the problem with complex chains of logic. Any defect breaks it. The term is not "valid," it is "proper." That is correct, a "proper sudoku" has one solution. By definition, not by some conclusory logic. --[[User:Abd|Abd]] ([[User talk:Abd|talk]]) 21:50, 15 January 2020 (UTC)
 
*B: A situation with multiple solutions is not something allowed in a valid sudoku
 
*B: A situation with multiple solutions is not something allowed in a valid sudoku
::'''''"Allowed" is again undefined. What is the authority that allows or does not allow? This special category, "valid sudoku" is used to imply that Sudoku with more than one solution are not Sudoku at all, when, by the definitions, they clearly are Sudoku, merely improper, which is a far less loaded term than "invalid."
+
::'''''"Allowed" is again undefined. What is the authority that allows or does not allow? This special category, "valid sudoku" is used to imply that Sudoku with more than one solution are not Sudoku at all, when, by the definitions, they clearly are Sudoku, merely improper, which is a far less loaded term than "invalid." --[[User:Abd|Abd]] ([[User talk:Abd|talk]]) 21:50, 15 January 2020 (UTC)
 
*C: uniqueness is a valid technique
 
*C: uniqueness is a valid technique
::'''''What does that mean? Valid for what? Not for logical proof!
+
::'''''What does that mean? Valid for what? Not for logical proof! But it is useful for faster solution of almost all Sudoku. --[[User:Abd|Abd]] ([[User talk:Abd|talk]]) 21:50, 15 January 2020 (UTC)
 
+
===Not arguing from authority===
 
So I hope that makes it clear that I'm not arguing from authority, just from the assumptions that we both agreed upon.
 
So I hope that makes it clear that I'm not arguing from authority, just from the assumptions that we both agreed upon.
:'''''We did not agree on those assumptions. And even if we do agree, uniqueness strategies are argument from authority -- which includes the "authority" of our personal experience. Much of the argument is is based on preference, not on fact, not on logic.
+
:'''''We did not agree on those assumptions. And even if we do agree, uniqueness strategies are argument from authority -- which includes the "authority" of our personal experience. Much of the argument is is based on preference, not on fact, not on logic. --[[User:Abd|Abd]] ([[User talk:Abd|talk]]) 21:50, 15 January 2020 (UTC)

Revision as of 23:06, 15 January 2020

What I see happening in this discussion is that a user was affronted personally and began, as a normal human response, to rationalize his positions, inventing or gathering arguments that are weak, and continuing to make assumptions about the topic and about what others were writing, that are not shared.

When we are offended, in general, our thinking goes awry, being dominated by survival reactions, and this is all stuff that I spent years studying and in training over. It is very human to do this, but it can create intractable disputes.

Pointing this out does not make any position "right" or "wrong," which are judgments, not actually facts. To move beyond this requires some caution and care. To really understand this may require reading the entire thread, which was not about persons, originally, but about Sudoku and a particular claimed uniqueness pattern. It became increasingly rude.

This also became a replay of common arguments about uniqueness, I've seen in many places. See the page supra.

Interesting uniqueness pattern comment reply

from sotolf2 via /r/sudoku Jan 15 2020 15:55 GMT - quoting u/Abdlomax (Abd on this wiki) Abd's original comment is in indented italic. Responses here should be further indented, in bold italic, and signed (with ~~~~) and may be refactored for clarity. --Abd (talk) 21:50, 15 January 2020 (UTC)


Definition of sudoku

Who said that uniqueness is "invalid"? Certainly not me! Rather, uniqueness is based on an assumption that was not stated when Sudoku were first formally defined and published. It was still assumed, by both authors and solvers. Some books add it as an afterthought.

So where is this authorative definition? I certainly haven't seen it anywhere, and I don't really belive one exists, if we are going to treat sudoku as a logic puzzle though it will have to have a logically deducable solution, something that is not possible if there are multiple solutions.

What is published is a picture of a puzzle with
You must place digits into the grid in such a way that every row, every column, and every 3x3 box contains each of the digits 1 through 9
This, or something very similar, is in every book on sudoku I have, which is many. As well, there are dictionary definitions. I'll link to Merriam-Webster. Given that there is no contrary definition shown, I'd call that "authoritative."
As well, the definitions claim nothing about logic or "logic puzzle". Rather, "solvable with logic" is a claim made about Sudoku, and SW Solver uses computer logic to crack any Sudoku, including multiple-solution Sodoku, reporting all solutions up to 500. --Abd (talk) 21:50, 15 January 2020 (UTC)

Is sudoku solving logic?

Can we agree that sudoku solving is logic?

Not if a puzzle has multiple solutions, if it does it will be logically unsolveable.

Counterexample given. --Abd (talk) 21:50, 15 January 2020 (UTC)

Any answer that satisfies the rules is "valid."

Any answer that satisfies the rules of of sudoku is "valid," so it is a solution. Claiming that guessing is required is not clear thinking.

I don't think I did, I might have though, but you can't logically deduce a solution if there are two valid solutions, unless you have some extra rules.

When we become personally involved in a dispute, defending ourselves, we become very concerned about what we said and did not say. What I wrote was clear and the user does not deny it, but then repeats his claim about what "can't be done," when it clearly can be done, is obviously done with SW Solver, and has been personally done by me, as I have reported. Underneath that is an assumption that solving a sodoku is finding one answer, and that if there is more than one, one must guess which it is, when if there is more than one, any answer still satisfied the problem presented by the puzzle. Finding "the answer" assumes only one. --Abd (talk) 21:50, 15 January 2020 (UTC)

"unsolvable without guessing

But then difficult puzzles began to be developed, considered "unsolvable without guessing." (And the language there was way cuckoo.)

I 100% agree with you in that.

Great! Let's build on that. --Abd (talk) 21:50, 15 January 2020 (UTC)

straw man argument

Sotolf2, you are creating a straw man argument, that someone claimed uniqueness is "invalid," when what is being said is that uniqueness is based on an additional assumption, not formally stated originally.

Again, until this "original" document of sudoku holiness is somewhere I can access it and see it I might agree with you, but I will assume that a sudoku puzzle should be logically deducible, or it is no longer a logic puzzle.

Becoming sarcastic, another relatively objective sign of attachment. I suggest looking at any Sudoku book or any dictionary. I've pointed out that unique-answer was an unstated assumption, an intention. But in this world, we do not always realize our intentions, and a puzzle created which has more than one solution is called "improper." Not "not a Sudoku." And these are solvable, that is, on can find numbers to fill in that satisfy the constraints. "Should be" is all personal judgment. And single-solution is not a requirement for logic puzzles. Again, it is normally intended. Math is a kind of logic. What is the square root of four? Find an answer and prove it. --Abd (talk) 21:50, 15 January 2020 (UTC)

An assumption of uniqueness proven invalid

What I did, among other things, was to prove that the assumption of uniqueness was invalid for this puzzle. That is most clearly accomplished by showing at least two.

This is what I personally classify as a bad puzzle, just as we would classify "10 They dog ago go buy days" as a bad English sentence even though it's kind of understandable it's still not a good sentence.

I find such puzzles interesting, and "bad" is a personal reaction, not a fact. Because "proper Sudoku" is objectively defined, we can agree that such a puzzle is improper. I happen to like some kinds of impropriety, in general. It's a personal choice; in general I recommend noticing such reactions -- which is what that is -- and digging up the roots and looking at them, because there can be found much that disempowers us. It is not therefore "bad" or "wrong," but the disempowerment can be very real. --Abd (talk) 21:50, 15 January 2020 (UTC)

u/the_gr8_n8 is solid

u/the_gr8_n8 is solid here

How so, he's assuming some kind of "Ground rules" that he still denies to supply. Also he's using rude language for no reason at all.

He was assuming nothing more than what I've shown above. You were asking him to supply what everyone knows, from his point of view. As to "rude language," the first rude language here was not from him. Using "hate" about an inanimate object is not "rude." It's rather ordinary speech. And he has not "denied to supply." That someone does not answer immediately is meaningless. It was not a refusal. But when we become attached, it all seems like an emergency that we must confront. --Abd (talk) 21:50, 15 January 2020 (UTC)

what does "I hate" mean?

Saying that I "hate" something is not a claim that it's wrong or bad or defective by some objective standard. It's simply how I feel

"Saying that I hate muslims is not Saying that I "hate" something is not a claim that it's wrong or bad or defective by some objective standard. It's simply how I feel"

Using an analogy like that is more evidence of attachment, setting aside the incoherence, which becomes common when we are attached. --Abd (talk) 21:50, 15 January 2020 (UTC)

Phrased like that don't you see that this doesn't really hold water?

No, I don't, the opposite. Equating "I hate [ethnic group]" is socially quite rude, even if true, and if true it is creating a social problem, because a group might decide to exclude "haters." But saying "I hate [object]" is simply an expression of a personal reaction. It was not rude, at all. It implies intensity, but is commonly used even without that. It simply means "I don't like it." As I wrote next. --Abd (talk) 21:50, 15 January 2020 (UTC)

hatred in ordinary speech can be just a feeling, not rude

Obviously, that "hatred" is weak, just a feeling that arises. I am also eager to get the candidate lists done, making them complete, and, overall, pleasure at that dominates.

Dislike and hate is not the same.

Again, the user is assuming that he has the authority to define the meaning of language. They are the same from some points of view, and different from others, which is like just about everything. In fact, "I dislike Muslims" could be almost as rude as "I hate Muslims." Depends on context. All Muslims? And all usages of uniqueness strategies? --Abd (talk) 21:50, 15 January 2020 (UTC)

assumption of possible solution

Yes, that a sudoku has any solution is also "up in the air," meaning unproven until the solution has been demonstrated by logic from the basics. Yet I and everyone else makes that assumption, because no-solution puzzles are even rarer than multiple-solution ones.

Yeah, so why is it okay to assume that the puzzle has any solutions but not that it has a single one?

Again we see the usage of undefined terms, not used by others, as if it what they believe. "Okay." What does that mean? And who has claimed that it is "not okay" to use the assumption of single solution? Nobody said that! --Abd (talk) 21:50, 15 January 2020 (UTC)

speed not Abd's goal

Because speed is not my goal (at all), I prefer to use uniqueness but not to depend on it. That's a preference, not some critique of uniqueness.

Yeah, I see nothing wrong about that at all, we all have preferences likes and dislikes, what I have a problem with is to claim others make "no good" assumptions, when it's a neccessity for what we all enjoy in a puzzle, that it's logically solvable.

Again, if someone made that claim, it wasn't me. "no good" was in quotes. Okay, who said it? Again, the user is also assuming that his experience is universal. All sudoku are logically solvable, so claiming the "necessity" of what is inevitable is odd. Again, the assumption underneath this is that unique-solution is necessary for enjoyment, when what we enjoy is about us, not about the puzzles. I enjoy all sudoku, except I've never tried to create them (which is more or less what the blank puzzle argument is about. I did, at one point, attempt to determine the error that made a puzzle multiple-solution. That was fun, so it stands as a counterargument to the "necessity" argument. (With a BUG puzzle, any of the BUG cells becoming a Given fixes the problem.) --Abd (talk) 21:50, 15 January 2020 (UTC)

pointing to uniqueness as-it-is interpreted as if hatred

It has happened here a number of times that if I pointed out that using uniqueness as if proof.
A fuller quote is needed here.
It has happened here a number of times that if I pointed out that using uniqueness as if proof was relying on argument from authority, and that was assumed to be "bad," and that therefore I "hated" uniqueness, all of which was straw man. It would be totally silly to hate routine reality! It is also routine reality that people make assumptions about what others mean, that are not necessarily valid. Argument from authority is considered a logical error, and errors are bad, right? Again, notice the reactive thinking. "Trial and error" is "bad," because it is "guessing" and both "guessing" and "error" are "bad."
The user actually agrees, though we have no definition of "valid." --Abd (talk) 21:50, 15 January 2020 (UTC)

I can agree that it will be wrong to use it as a proof, as it isn't really, as a shortcut to solving, like colouring or fishes or anything I don't see how it's any less valid than anything else.

Nobody has claimed that it is not "valid." Rather it has been claimed that it is a form of argument from authority, specifically from authority that is quite reliable, but not infallible. To use it or not is a personal choice. It is only "invalid" as a logical proof, but it is totally valid (i.e, completely reasonable) as a heuristic. What I've been promoting is an awareness of the difference, and of the (very small) risk, that using a uniqueness strategy can cover up the existence of additional answers or, even more rarely, break a puzzle. --Abd (talk) 21:50, 15 January 2020 (UTC)

meaning of argument from authority

argument from authority

An arguement from authority would be to claim that someone makes an assumption based on something like someone said, like "It's not part of the original definition of sudoku" And I'm not the one claiming that.

This is incoherent, but does it matter? Authority is here being confused with verifiable reality. The "original definition" was actually example, published puzzles with rules, and they all agree. The dictionary definitions follow that and the obvious. All that was said was that uniqueness was not part of the original definition, which it wasn't. Yes, the other user and I claimed that, and it's verifiable and no counter-example has been asserted. It's just fact. And it is also fact -- apparently -- that it was routinely assumed that published puzzles would have only one solution. But that was an assumption based on intention, not a fact, though supported by widespread experience that all puzzles -- in one person's experience -- have only one solution. What's the reality here? I don't think there is an real disagreement about it, but only over a pile of "shoulds" and "likes" and "better thans." --Abd (talk) 21:50, 15 January 2020 (UTC)

For me guessing would be to go with something before you have a convincing reason to go for it, which I don't think colouring is, colouring is not guessing, and neither is uniqueness. Not that I think guessing would not be a valid way to get to a solution, it's just not one that I like to use myself.

Uniqueness is not guessing in itself. It is noticing a pattern that, if the solution requires it, would have more than one solution, and then using that pattern to solve the puzzle is "guessing" that the puzzle is not an exception. But a guess that can be expected to be "correct," almost all the time, is not what we would ordinarily call guessing. It is inference from what is common and normal, with exceptions being quite rare. Simply not a proof. --Abd (talk) 21:52, 15 January 2020 (UTC)

I just get annoyed when someone claims I make assumptions that "Are not valid" and they themselves aren't able to make at least some reasoning without acting out and being rude like was the case here.

Right. And I get annoyed when someone asserts I claimed something I did not claim, or does this about someone else. First question, for me, is "was this claimed?" If so, I'll write "Damn straight!" And if not, I'll object. Or not. Depends on the effect I expect. The claims that I "hated uniqueness" I considered potentially damaging, so I confronted them. But the other user here was really just saying "I hate to use uniqueness," which is ordinary speech and not offensive, and I pointed out that it could be disempowering, because noticing a uniqueness strategy can be useful. Just not a proof! So if we want proof, we won't rely on it, we will use direct logic, without the assumption.
But if we just want to get the freaking answer, and don't care about proving uniqueness, we'll use it.
Neither of these approaches are "valid" or "invalid." They are choices and, as such, they are useful or not. I happen to enjoy doing sudoku, and requiring proof of uniqueness requires that I do more sudoku logic. I happen to consider that fun. So I do wonder about people that avoid it, but don't question for a moment their right to make the choice.
I ask the question here: if it is only a little more process -- or not even much more at all -- to prove uniqueness rather than assume it, what will you choose?
I do not propose that either choice is wrong or "invalid." It is like choosing a seed pair for SBN. There is no wrong choice. There are choices that require more patience than others, and patience is a fantastic thing to develop, but when and where to do that is all about personal choice, not "right" and "wrong." --Abd (talk) 21:50, 15 January 2020 (UTC)

suggested syllogisms

So I suggest the syllogisms

First

  • A: Sudoku is a logical puzzle
That is a description of process we have developed to solve sudoku, not of sudoku themselves. Sudoku are patterns of numbers in a grid, with blanks, and a suggestion to fill in the blanks with more numbers to solve it, satisfying the rules. How we do that is not stated. We could guess, and if we find a solution that way -- pure guessing is damned inefficient! -- it would still be a solution if it satisfies the rules. --Abd (talk) 21:50, 15 January 2020 (UTC)
  • B: All logical puzzle has to be solvable by logic.
That assumes the conclusion. We make that assumption, it also was not stated. A puzzle may come to us that has no solution. They are rare, but they exist. They are still puzzles, and they are still "solvable by logic" in the sense that logic can prove that there is no solution. --Abd (talk) 21:50, 15 January 2020 (UTC)
  • C: Sudoku has to be solveable by logic
Conclusion created by assumptions. In fact, with a reasonable definition of "solveable," all sudoku are solvable. There might be a very large number of possible solutions. --Abd (talk) 21:50, 15 January 2020 (UTC)

Second

  • A: Sudoku has to be solveable by logic
garbage in, garbage out. "Has to be" is undefined. It is the language of compulsion and assumptions about what must be or else . . . or else what? Given that all sudoku are solvable by logic, this is meaningless. --Abd (talk) 21:50, 15 January 2020 (UTC)
  • B: A puzzle with multiple solutions aren't solveable by logic
This assumes single solution in "solvable." But if a puzzle has two and only two solutions, logic can find both of them. Either one is a solution, satisfying the rules, and showing both completely solves the puzzle, no questions. --Abd (talk) 21:50, 15 January 2020 (UTC)
  • C: Sudoku with multiple solutions are not valid
"Not valid" is undefined. The term "improper:" was developed to describe Sudoku with no solution or with multiple solutions. --Abd (talk) 21:50, 15 January 2020 (UTC)

Third

  • A: A valid sudoku has one solution
This is the problem with complex chains of logic. Any defect breaks it. The term is not "valid," it is "proper." That is correct, a "proper sudoku" has one solution. By definition, not by some conclusory logic. --Abd (talk) 21:50, 15 January 2020 (UTC)
  • B: A situation with multiple solutions is not something allowed in a valid sudoku
"Allowed" is again undefined. What is the authority that allows or does not allow? This special category, "valid sudoku" is used to imply that Sudoku with more than one solution are not Sudoku at all, when, by the definitions, they clearly are Sudoku, merely improper, which is a far less loaded term than "invalid." --Abd (talk) 21:50, 15 January 2020 (UTC)
  • C: uniqueness is a valid technique
What does that mean? Valid for what? Not for logical proof! But it is useful for faster solution of almost all Sudoku. --Abd (talk) 21:50, 15 January 2020 (UTC)

Not arguing from authority

So I hope that makes it clear that I'm not arguing from authority, just from the assumptions that we both agreed upon.

We did not agree on those assumptions. And even if we do agree, uniqueness strategies are argument from authority -- which includes the "authority" of our personal experience. Much of the argument is is based on preference, not on fact, not on logic. --Abd (talk) 21:50, 15 January 2020 (UTC)