Quantifier difference











up vote
0
down vote

favorite












What s the difference between $ n in Z implies n(n+1) =2k $ such that $k in Z$ and $ forall n in Z implies n(n+1) =2k $ such that $k in Z$



Is this true:
$ (n in Z implies n(n+1) =2k $ such that $k in Z) implies forall n in Z; n(n+1) =2k $ such that$ k in Z$










share|cite|improve this question
























  • None, in that I cannot understand either: why have you introduced a $k$, only to use it in the expression $2k/k$ which merely simplifies to $2$?
    – Lord Shark the Unknown
    Nov 19 at 7:15










  • / means such that in my case
    – J.Moh
    Nov 19 at 8:19










  • Impossible to understand ... The first one is an equation : $dfrac {n}{n+1}=2k$.
    – Mauro ALLEGRANZA
    Nov 19 at 10:32










  • The second one is a formula : $(dfrac {n}{n+1}=2k) to forall n (dfrac {n}{n+1}=2k)$ whose truth value depends on $n$ and $k$.
    – Mauro ALLEGRANZA
    Nov 19 at 10:33












  • Rewritten in an unambiguous way
    – J.Moh
    Nov 19 at 10:47















up vote
0
down vote

favorite












What s the difference between $ n in Z implies n(n+1) =2k $ such that $k in Z$ and $ forall n in Z implies n(n+1) =2k $ such that $k in Z$



Is this true:
$ (n in Z implies n(n+1) =2k $ such that $k in Z) implies forall n in Z; n(n+1) =2k $ such that$ k in Z$










share|cite|improve this question
























  • None, in that I cannot understand either: why have you introduced a $k$, only to use it in the expression $2k/k$ which merely simplifies to $2$?
    – Lord Shark the Unknown
    Nov 19 at 7:15










  • / means such that in my case
    – J.Moh
    Nov 19 at 8:19










  • Impossible to understand ... The first one is an equation : $dfrac {n}{n+1}=2k$.
    – Mauro ALLEGRANZA
    Nov 19 at 10:32










  • The second one is a formula : $(dfrac {n}{n+1}=2k) to forall n (dfrac {n}{n+1}=2k)$ whose truth value depends on $n$ and $k$.
    – Mauro ALLEGRANZA
    Nov 19 at 10:33












  • Rewritten in an unambiguous way
    – J.Moh
    Nov 19 at 10:47













up vote
0
down vote

favorite









up vote
0
down vote

favorite











What s the difference between $ n in Z implies n(n+1) =2k $ such that $k in Z$ and $ forall n in Z implies n(n+1) =2k $ such that $k in Z$



Is this true:
$ (n in Z implies n(n+1) =2k $ such that $k in Z) implies forall n in Z; n(n+1) =2k $ such that$ k in Z$










share|cite|improve this question















What s the difference between $ n in Z implies n(n+1) =2k $ such that $k in Z$ and $ forall n in Z implies n(n+1) =2k $ such that $k in Z$



Is this true:
$ (n in Z implies n(n+1) =2k $ such that $k in Z) implies forall n in Z; n(n+1) =2k $ such that$ k in Z$







quantifiers






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Nov 19 at 10:45

























asked Nov 19 at 6:45









J.Moh

395




395












  • None, in that I cannot understand either: why have you introduced a $k$, only to use it in the expression $2k/k$ which merely simplifies to $2$?
    – Lord Shark the Unknown
    Nov 19 at 7:15










  • / means such that in my case
    – J.Moh
    Nov 19 at 8:19










  • Impossible to understand ... The first one is an equation : $dfrac {n}{n+1}=2k$.
    – Mauro ALLEGRANZA
    Nov 19 at 10:32










  • The second one is a formula : $(dfrac {n}{n+1}=2k) to forall n (dfrac {n}{n+1}=2k)$ whose truth value depends on $n$ and $k$.
    – Mauro ALLEGRANZA
    Nov 19 at 10:33












  • Rewritten in an unambiguous way
    – J.Moh
    Nov 19 at 10:47


















  • None, in that I cannot understand either: why have you introduced a $k$, only to use it in the expression $2k/k$ which merely simplifies to $2$?
    – Lord Shark the Unknown
    Nov 19 at 7:15










  • / means such that in my case
    – J.Moh
    Nov 19 at 8:19










  • Impossible to understand ... The first one is an equation : $dfrac {n}{n+1}=2k$.
    – Mauro ALLEGRANZA
    Nov 19 at 10:32










  • The second one is a formula : $(dfrac {n}{n+1}=2k) to forall n (dfrac {n}{n+1}=2k)$ whose truth value depends on $n$ and $k$.
    – Mauro ALLEGRANZA
    Nov 19 at 10:33












  • Rewritten in an unambiguous way
    – J.Moh
    Nov 19 at 10:47
















None, in that I cannot understand either: why have you introduced a $k$, only to use it in the expression $2k/k$ which merely simplifies to $2$?
– Lord Shark the Unknown
Nov 19 at 7:15




None, in that I cannot understand either: why have you introduced a $k$, only to use it in the expression $2k/k$ which merely simplifies to $2$?
– Lord Shark the Unknown
Nov 19 at 7:15












/ means such that in my case
– J.Moh
Nov 19 at 8:19




/ means such that in my case
– J.Moh
Nov 19 at 8:19












Impossible to understand ... The first one is an equation : $dfrac {n}{n+1}=2k$.
– Mauro ALLEGRANZA
Nov 19 at 10:32




Impossible to understand ... The first one is an equation : $dfrac {n}{n+1}=2k$.
– Mauro ALLEGRANZA
Nov 19 at 10:32












The second one is a formula : $(dfrac {n}{n+1}=2k) to forall n (dfrac {n}{n+1}=2k)$ whose truth value depends on $n$ and $k$.
– Mauro ALLEGRANZA
Nov 19 at 10:33






The second one is a formula : $(dfrac {n}{n+1}=2k) to forall n (dfrac {n}{n+1}=2k)$ whose truth value depends on $n$ and $k$.
– Mauro ALLEGRANZA
Nov 19 at 10:33














Rewritten in an unambiguous way
– J.Moh
Nov 19 at 10:47




Rewritten in an unambiguous way
– J.Moh
Nov 19 at 10:47










1 Answer
1






active

oldest

votes

















up vote
0
down vote














Is this true that :




$(n ∈ mathbb Z ⟹ dfrac {n}{(n+1)} = 2k ) ⟹ ∀n ∈ mathbb Z dfrac {n}{(n+1)} = 2k text { , for } k ∈ mathbb Z$ ?





The formula :




$dfrac {n}{(n+1)} = 2k$




is about two unspecified numbers $n$ and $k$; it can be either true or false, according to the values we assign to them.



Specifically, the formula is true only for $n=k=0$.



This means that the consequent : $∀n ∈ mathbb Z dfrac {n}{(n+1)} = 2k$ is false.



Thus the original formula is false for $n=k=0$ (because in that case we have $text T to text F$, which is $text F$) and true in all other cases (because $text F to text F$ is $text T$).






share|cite|improve this answer























  • / doesn t mean division in my case, it means such that
    – J.Moh
    Nov 19 at 8:18













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: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
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%2f3004598%2fquantifier-difference%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown

























1 Answer
1






active

oldest

votes








1 Answer
1






active

oldest

votes









active

oldest

votes






active

oldest

votes








up vote
0
down vote














Is this true that :




$(n ∈ mathbb Z ⟹ dfrac {n}{(n+1)} = 2k ) ⟹ ∀n ∈ mathbb Z dfrac {n}{(n+1)} = 2k text { , for } k ∈ mathbb Z$ ?





The formula :




$dfrac {n}{(n+1)} = 2k$




is about two unspecified numbers $n$ and $k$; it can be either true or false, according to the values we assign to them.



Specifically, the formula is true only for $n=k=0$.



This means that the consequent : $∀n ∈ mathbb Z dfrac {n}{(n+1)} = 2k$ is false.



Thus the original formula is false for $n=k=0$ (because in that case we have $text T to text F$, which is $text F$) and true in all other cases (because $text F to text F$ is $text T$).






share|cite|improve this answer























  • / doesn t mean division in my case, it means such that
    – J.Moh
    Nov 19 at 8:18

















up vote
0
down vote














Is this true that :




$(n ∈ mathbb Z ⟹ dfrac {n}{(n+1)} = 2k ) ⟹ ∀n ∈ mathbb Z dfrac {n}{(n+1)} = 2k text { , for } k ∈ mathbb Z$ ?





The formula :




$dfrac {n}{(n+1)} = 2k$




is about two unspecified numbers $n$ and $k$; it can be either true or false, according to the values we assign to them.



Specifically, the formula is true only for $n=k=0$.



This means that the consequent : $∀n ∈ mathbb Z dfrac {n}{(n+1)} = 2k$ is false.



Thus the original formula is false for $n=k=0$ (because in that case we have $text T to text F$, which is $text F$) and true in all other cases (because $text F to text F$ is $text T$).






share|cite|improve this answer























  • / doesn t mean division in my case, it means such that
    – J.Moh
    Nov 19 at 8:18















up vote
0
down vote










up vote
0
down vote










Is this true that :




$(n ∈ mathbb Z ⟹ dfrac {n}{(n+1)} = 2k ) ⟹ ∀n ∈ mathbb Z dfrac {n}{(n+1)} = 2k text { , for } k ∈ mathbb Z$ ?





The formula :




$dfrac {n}{(n+1)} = 2k$




is about two unspecified numbers $n$ and $k$; it can be either true or false, according to the values we assign to them.



Specifically, the formula is true only for $n=k=0$.



This means that the consequent : $∀n ∈ mathbb Z dfrac {n}{(n+1)} = 2k$ is false.



Thus the original formula is false for $n=k=0$ (because in that case we have $text T to text F$, which is $text F$) and true in all other cases (because $text F to text F$ is $text T$).






share|cite|improve this answer















Is this true that :




$(n ∈ mathbb Z ⟹ dfrac {n}{(n+1)} = 2k ) ⟹ ∀n ∈ mathbb Z dfrac {n}{(n+1)} = 2k text { , for } k ∈ mathbb Z$ ?





The formula :




$dfrac {n}{(n+1)} = 2k$




is about two unspecified numbers $n$ and $k$; it can be either true or false, according to the values we assign to them.



Specifically, the formula is true only for $n=k=0$.



This means that the consequent : $∀n ∈ mathbb Z dfrac {n}{(n+1)} = 2k$ is false.



Thus the original formula is false for $n=k=0$ (because in that case we have $text T to text F$, which is $text F$) and true in all other cases (because $text F to text F$ is $text T$).







share|cite|improve this answer














share|cite|improve this answer



share|cite|improve this answer








edited Nov 19 at 10:55

























answered Nov 19 at 7:13









Mauro ALLEGRANZA

63.8k448110




63.8k448110












  • / doesn t mean division in my case, it means such that
    – J.Moh
    Nov 19 at 8:18




















  • / doesn t mean division in my case, it means such that
    – J.Moh
    Nov 19 at 8:18


















/ doesn t mean division in my case, it means such that
– J.Moh
Nov 19 at 8:18






/ doesn t mean division in my case, it means such that
– J.Moh
Nov 19 at 8:18




















draft saved

draft discarded




















































Thanks for contributing an answer to Mathematics Stack Exchange!


  • Please be sure to answer the question. Provide details and share your research!

But avoid



  • Asking for help, clarification, or responding to other answers.

  • Making statements based on opinion; back them up with references or personal experience.


Use MathJax to format equations. MathJax reference.


To learn more, see our tips on writing great answers.





Some of your past answers have not been well-received, and you're in danger of being blocked from answering.


Please pay close attention to the following guidance:


  • Please be sure to answer the question. Provide details and share your research!

But avoid



  • Asking for help, clarification, or responding to other answers.

  • Making statements based on opinion; back them up with references or personal experience.


To learn more, see our tips on writing great answers.




draft saved


draft discarded














StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3004598%2fquantifier-difference%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown





















































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown

































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown







Popular posts from this blog

How to change which sound is reproduced for terminal bell?

Can I use Tabulator js library in my java Spring + Thymeleaf project?

Title Spacing in Bjornstrup Chapter, Removing Chapter Number From Contents