How this statement should be written?

The name of the pictureThe name of the pictureThe name of the pictureClash Royale CLAN TAG#URR8PPP











up vote
0
down vote

favorite












If I have a theorem/conjecture of the form "Let $n$ be an [object with some properties], then $P(n)$", how would it be written in logic ? So I have 2 variants:

1)$forall n in A, P(n)$.

2)$(nin A)to(P(n))$.

(By $A$ I mean a set of all such objects with some property).

So is one of my variants right ? Or it should be written in some other form ?







share|cite|improve this question





















  • So it would be kind of equivalent ?
    – Ð®Ñ€Ñ–й Ярош
    Aug 2 at 10:01










  • @MauroALLEGRANZA No I meant,are variants I have written equivalent ?Because in my second variant I have no quantifiers, or we can transform second variant using universal generalization ?
    – Ð®Ñ€Ñ–й Ярош
    Aug 2 at 10:04











  • @MauroALLEGRANZA Yeah, now I realized that the second statement can be true some $n$ and false for the others, so I need "for all" claim anyway, thanks for explaining.
    – Ð®Ñ€Ñ–й Ярош
    Aug 2 at 10:22










  • In so-called 'Agda notation' for dependent type theory, the notation $(n in A) to P(n)$ refers to the dependent product type $prod_n in A P(n)$, which corresponds with the proposition $forall n in A,,P(n)$ under the Curry-Howard correspondence. I'm leaving this as a comment rather than an answer because it would not be considered correct notation in mainstream mathematics.
    – Clive Newstead
    Aug 2 at 14:26















up vote
0
down vote

favorite












If I have a theorem/conjecture of the form "Let $n$ be an [object with some properties], then $P(n)$", how would it be written in logic ? So I have 2 variants:

1)$forall n in A, P(n)$.

2)$(nin A)to(P(n))$.

(By $A$ I mean a set of all such objects with some property).

So is one of my variants right ? Or it should be written in some other form ?







share|cite|improve this question





















  • So it would be kind of equivalent ?
    – Ð®Ñ€Ñ–й Ярош
    Aug 2 at 10:01










  • @MauroALLEGRANZA No I meant,are variants I have written equivalent ?Because in my second variant I have no quantifiers, or we can transform second variant using universal generalization ?
    – Ð®Ñ€Ñ–й Ярош
    Aug 2 at 10:04











  • @MauroALLEGRANZA Yeah, now I realized that the second statement can be true some $n$ and false for the others, so I need "for all" claim anyway, thanks for explaining.
    – Ð®Ñ€Ñ–й Ярош
    Aug 2 at 10:22










  • In so-called 'Agda notation' for dependent type theory, the notation $(n in A) to P(n)$ refers to the dependent product type $prod_n in A P(n)$, which corresponds with the proposition $forall n in A,,P(n)$ under the Curry-Howard correspondence. I'm leaving this as a comment rather than an answer because it would not be considered correct notation in mainstream mathematics.
    – Clive Newstead
    Aug 2 at 14:26













up vote
0
down vote

favorite









up vote
0
down vote

favorite











If I have a theorem/conjecture of the form "Let $n$ be an [object with some properties], then $P(n)$", how would it be written in logic ? So I have 2 variants:

1)$forall n in A, P(n)$.

2)$(nin A)to(P(n))$.

(By $A$ I mean a set of all such objects with some property).

So is one of my variants right ? Or it should be written in some other form ?







share|cite|improve this question













If I have a theorem/conjecture of the form "Let $n$ be an [object with some properties], then $P(n)$", how would it be written in logic ? So I have 2 variants:

1)$forall n in A, P(n)$.

2)$(nin A)to(P(n))$.

(By $A$ I mean a set of all such objects with some property).

So is one of my variants right ? Or it should be written in some other form ?









share|cite|improve this question












share|cite|improve this question




share|cite|improve this question








edited Aug 2 at 10:58









Bram28

54.5k33880




54.5k33880









asked Aug 2 at 9:55









Юрій Ярош

979412




979412











  • So it would be kind of equivalent ?
    – Ð®Ñ€Ñ–й Ярош
    Aug 2 at 10:01










  • @MauroALLEGRANZA No I meant,are variants I have written equivalent ?Because in my second variant I have no quantifiers, or we can transform second variant using universal generalization ?
    – Ð®Ñ€Ñ–й Ярош
    Aug 2 at 10:04











  • @MauroALLEGRANZA Yeah, now I realized that the second statement can be true some $n$ and false for the others, so I need "for all" claim anyway, thanks for explaining.
    – Ð®Ñ€Ñ–й Ярош
    Aug 2 at 10:22










  • In so-called 'Agda notation' for dependent type theory, the notation $(n in A) to P(n)$ refers to the dependent product type $prod_n in A P(n)$, which corresponds with the proposition $forall n in A,,P(n)$ under the Curry-Howard correspondence. I'm leaving this as a comment rather than an answer because it would not be considered correct notation in mainstream mathematics.
    – Clive Newstead
    Aug 2 at 14:26

















  • So it would be kind of equivalent ?
    – Ð®Ñ€Ñ–й Ярош
    Aug 2 at 10:01










  • @MauroALLEGRANZA No I meant,are variants I have written equivalent ?Because in my second variant I have no quantifiers, or we can transform second variant using universal generalization ?
    – Ð®Ñ€Ñ–й Ярош
    Aug 2 at 10:04











  • @MauroALLEGRANZA Yeah, now I realized that the second statement can be true some $n$ and false for the others, so I need "for all" claim anyway, thanks for explaining.
    – Ð®Ñ€Ñ–й Ярош
    Aug 2 at 10:22










  • In so-called 'Agda notation' for dependent type theory, the notation $(n in A) to P(n)$ refers to the dependent product type $prod_n in A P(n)$, which corresponds with the proposition $forall n in A,,P(n)$ under the Curry-Howard correspondence. I'm leaving this as a comment rather than an answer because it would not be considered correct notation in mainstream mathematics.
    – Clive Newstead
    Aug 2 at 14:26
















So it would be kind of equivalent ?
– Ð®Ñ€Ñ–й Ярош
Aug 2 at 10:01




So it would be kind of equivalent ?
– Ð®Ñ€Ñ–й Ярош
Aug 2 at 10:01












@MauroALLEGRANZA No I meant,are variants I have written equivalent ?Because in my second variant I have no quantifiers, or we can transform second variant using universal generalization ?
– Ð®Ñ€Ñ–й Ярош
Aug 2 at 10:04





@MauroALLEGRANZA No I meant,are variants I have written equivalent ?Because in my second variant I have no quantifiers, or we can transform second variant using universal generalization ?
– Ð®Ñ€Ñ–й Ярош
Aug 2 at 10:04













@MauroALLEGRANZA Yeah, now I realized that the second statement can be true some $n$ and false for the others, so I need "for all" claim anyway, thanks for explaining.
– Ð®Ñ€Ñ–й Ярош
Aug 2 at 10:22




@MauroALLEGRANZA Yeah, now I realized that the second statement can be true some $n$ and false for the others, so I need "for all" claim anyway, thanks for explaining.
– Ð®Ñ€Ñ–й Ярош
Aug 2 at 10:22












In so-called 'Agda notation' for dependent type theory, the notation $(n in A) to P(n)$ refers to the dependent product type $prod_n in A P(n)$, which corresponds with the proposition $forall n in A,,P(n)$ under the Curry-Howard correspondence. I'm leaving this as a comment rather than an answer because it would not be considered correct notation in mainstream mathematics.
– Clive Newstead
Aug 2 at 14:26





In so-called 'Agda notation' for dependent type theory, the notation $(n in A) to P(n)$ refers to the dependent product type $prod_n in A P(n)$, which corresponds with the proposition $forall n in A,,P(n)$ under the Curry-Howard correspondence. I'm leaving this as a comment rather than an answer because it would not be considered correct notation in mainstream mathematics.
– Clive Newstead
Aug 2 at 14:26











1 Answer
1






active

oldest

votes

















up vote
4
down vote



accepted










$(nin A)to P(n)$ is a good start, but you need something to express the idea that you want this to be true for all $n$. So you should write
$$ forall n : bigl[ nin A to P(n) bigr] $$



This is what "$forall nin A. P(n)$" (with variations in punctuation that don't carry any meaning) is usually considered to be an abbreviation for in formal logic.






share|cite|improve this answer























    Your Answer




    StackExchange.ifUsing("editor", function ()
    return StackExchange.using("mathjaxEditing", function ()
    StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix)
    StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
    );
    );
    , "mathjax-editing");

    StackExchange.ready(function()
    var channelOptions =
    tags: "".split(" "),
    id: "69"
    ;
    initTagRenderer("".split(" "), "".split(" "), channelOptions);

    StackExchange.using("externalEditor", function()
    // Have to fire editor after snippets, if snippets enabled
    if (StackExchange.settings.snippets.snippetsEnabled)
    StackExchange.using("snippets", function()
    createEditor();
    );

    else
    createEditor();

    );

    function createEditor()
    StackExchange.prepareEditor(
    heartbeatType: 'answer',
    convertImagesToLinks: true,
    noModals: false,
    showLowRepImageUploadWarning: true,
    reputationToPostImages: 10,
    bindNavPrevention: true,
    postfix: "",
    noCode: true, onDemand: true,
    discardSelector: ".discard-answer"
    ,immediatelyShowMarkdownHelp:true
    );



    );








     

    draft saved


    draft discarded


















    StackExchange.ready(
    function ()
    StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f2869896%2fhow-this-statement-should-be-written%23new-answer', 'question_page');

    );

    Post as a guest






























    1 Answer
    1






    active

    oldest

    votes








    1 Answer
    1






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes








    up vote
    4
    down vote



    accepted










    $(nin A)to P(n)$ is a good start, but you need something to express the idea that you want this to be true for all $n$. So you should write
    $$ forall n : bigl[ nin A to P(n) bigr] $$



    This is what "$forall nin A. P(n)$" (with variations in punctuation that don't carry any meaning) is usually considered to be an abbreviation for in formal logic.






    share|cite|improve this answer



























      up vote
      4
      down vote



      accepted










      $(nin A)to P(n)$ is a good start, but you need something to express the idea that you want this to be true for all $n$. So you should write
      $$ forall n : bigl[ nin A to P(n) bigr] $$



      This is what "$forall nin A. P(n)$" (with variations in punctuation that don't carry any meaning) is usually considered to be an abbreviation for in formal logic.






      share|cite|improve this answer

























        up vote
        4
        down vote



        accepted







        up vote
        4
        down vote



        accepted






        $(nin A)to P(n)$ is a good start, but you need something to express the idea that you want this to be true for all $n$. So you should write
        $$ forall n : bigl[ nin A to P(n) bigr] $$



        This is what "$forall nin A. P(n)$" (with variations in punctuation that don't carry any meaning) is usually considered to be an abbreviation for in formal logic.






        share|cite|improve this answer















        $(nin A)to P(n)$ is a good start, but you need something to express the idea that you want this to be true for all $n$. So you should write
        $$ forall n : bigl[ nin A to P(n) bigr] $$



        This is what "$forall nin A. P(n)$" (with variations in punctuation that don't carry any meaning) is usually considered to be an abbreviation for in formal logic.







        share|cite|improve this answer















        share|cite|improve this answer



        share|cite|improve this answer








        edited Aug 2 at 14:22


























        answered Aug 2 at 11:08









        Henning Makholm

        225k16290516




        225k16290516






















             

            draft saved


            draft discarded


























             


            draft saved


            draft discarded














            StackExchange.ready(
            function ()
            StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f2869896%2fhow-this-statement-should-be-written%23new-answer', 'question_page');

            );

            Post as a guest













































































            Comments

            Popular posts from this blog

            What is the equation of a 3D cone with generalised tilt?

            Relationship between determinant of matrix and determinant of adjoint?

            Color the edges and diagonals of a regular polygon