Let $E$ be an inductive ordered set, then $forall ain E$ ($exists$ a maximal element $min E$ $ni$ $aleq m$)












0












$begingroup$


I read the following in a book:
Theorem: Let $E$ be an inductive ordered set and let $a$ be and element of $E$. Then there exists a maximal element $m$ of $E$ such that $mgeq a$.



If I understand correctly, an inductive ordered set does not necessarily have to be totally ordered. So $a$ can be an element that's not comparable to any other element of $E$. Then there exists no $m$ such that $mgeq a$. Shouldn't we add a condition: $a$ is comparable to some element in $E$?










share|cite|improve this question











$endgroup$








  • 3




    $begingroup$
    $a$ is always comparable to $a$
    $endgroup$
    – Max
    Feb 2 at 21:47










  • $begingroup$
    @Max That's it! Thanks.
    $endgroup$
    – Ali
    Feb 2 at 22:13










  • $begingroup$
    The positive integers N, are inductively ordered and though 1 in N, there is no maximal number > 1.
    $endgroup$
    – William Elliot
    Feb 3 at 0:22










  • $begingroup$
    @WilliamElliot Interesting! Apparently this theorem only works for finite sets.
    $endgroup$
    – Ali
    Feb 3 at 0:29
















0












$begingroup$


I read the following in a book:
Theorem: Let $E$ be an inductive ordered set and let $a$ be and element of $E$. Then there exists a maximal element $m$ of $E$ such that $mgeq a$.



If I understand correctly, an inductive ordered set does not necessarily have to be totally ordered. So $a$ can be an element that's not comparable to any other element of $E$. Then there exists no $m$ such that $mgeq a$. Shouldn't we add a condition: $a$ is comparable to some element in $E$?










share|cite|improve this question











$endgroup$








  • 3




    $begingroup$
    $a$ is always comparable to $a$
    $endgroup$
    – Max
    Feb 2 at 21:47










  • $begingroup$
    @Max That's it! Thanks.
    $endgroup$
    – Ali
    Feb 2 at 22:13










  • $begingroup$
    The positive integers N, are inductively ordered and though 1 in N, there is no maximal number > 1.
    $endgroup$
    – William Elliot
    Feb 3 at 0:22










  • $begingroup$
    @WilliamElliot Interesting! Apparently this theorem only works for finite sets.
    $endgroup$
    – Ali
    Feb 3 at 0:29














0












0








0





$begingroup$


I read the following in a book:
Theorem: Let $E$ be an inductive ordered set and let $a$ be and element of $E$. Then there exists a maximal element $m$ of $E$ such that $mgeq a$.



If I understand correctly, an inductive ordered set does not necessarily have to be totally ordered. So $a$ can be an element that's not comparable to any other element of $E$. Then there exists no $m$ such that $mgeq a$. Shouldn't we add a condition: $a$ is comparable to some element in $E$?










share|cite|improve this question











$endgroup$




I read the following in a book:
Theorem: Let $E$ be an inductive ordered set and let $a$ be and element of $E$. Then there exists a maximal element $m$ of $E$ such that $mgeq a$.



If I understand correctly, an inductive ordered set does not necessarily have to be totally ordered. So $a$ can be an element that's not comparable to any other element of $E$. Then there exists no $m$ such that $mgeq a$. Shouldn't we add a condition: $a$ is comparable to some element in $E$?







elementary-set-theory






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Feb 3 at 1:21









Andrés E. Caicedo

66k8160252




66k8160252










asked Feb 2 at 21:34









AliAli

1057




1057








  • 3




    $begingroup$
    $a$ is always comparable to $a$
    $endgroup$
    – Max
    Feb 2 at 21:47










  • $begingroup$
    @Max That's it! Thanks.
    $endgroup$
    – Ali
    Feb 2 at 22:13










  • $begingroup$
    The positive integers N, are inductively ordered and though 1 in N, there is no maximal number > 1.
    $endgroup$
    – William Elliot
    Feb 3 at 0:22










  • $begingroup$
    @WilliamElliot Interesting! Apparently this theorem only works for finite sets.
    $endgroup$
    – Ali
    Feb 3 at 0:29














  • 3




    $begingroup$
    $a$ is always comparable to $a$
    $endgroup$
    – Max
    Feb 2 at 21:47










  • $begingroup$
    @Max That's it! Thanks.
    $endgroup$
    – Ali
    Feb 2 at 22:13










  • $begingroup$
    The positive integers N, are inductively ordered and though 1 in N, there is no maximal number > 1.
    $endgroup$
    – William Elliot
    Feb 3 at 0:22










  • $begingroup$
    @WilliamElliot Interesting! Apparently this theorem only works for finite sets.
    $endgroup$
    – Ali
    Feb 3 at 0:29








3




3




$begingroup$
$a$ is always comparable to $a$
$endgroup$
– Max
Feb 2 at 21:47




$begingroup$
$a$ is always comparable to $a$
$endgroup$
– Max
Feb 2 at 21:47












$begingroup$
@Max That's it! Thanks.
$endgroup$
– Ali
Feb 2 at 22:13




$begingroup$
@Max That's it! Thanks.
$endgroup$
– Ali
Feb 2 at 22:13












$begingroup$
The positive integers N, are inductively ordered and though 1 in N, there is no maximal number > 1.
$endgroup$
– William Elliot
Feb 3 at 0:22




$begingroup$
The positive integers N, are inductively ordered and though 1 in N, there is no maximal number > 1.
$endgroup$
– William Elliot
Feb 3 at 0:22












$begingroup$
@WilliamElliot Interesting! Apparently this theorem only works for finite sets.
$endgroup$
– Ali
Feb 3 at 0:29




$begingroup$
@WilliamElliot Interesting! Apparently this theorem only works for finite sets.
$endgroup$
– Ali
Feb 3 at 0:29










0






active

oldest

votes












Your Answer








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',
autoActivateHeartbeat: false,
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%2f3097827%2flet-e-be-an-inductive-ordered-set-then-forall-a-in-e-exists-a-maximal%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown

























0






active

oldest

votes








0






active

oldest

votes









active

oldest

votes






active

oldest

votes
















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.




draft saved


draft discarded














StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3097827%2flet-e-be-an-inductive-ordered-set-then-forall-a-in-e-exists-a-maximal%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

MongoDB - Not Authorized To Execute Command

in spring boot 2.1 many test slices are not allowed anymore due to multiple @BootstrapWith

Npm cannot find a required file even through it is in the searched directory