Non-isomorphic connected bipartite simple graphs
$begingroup$
How many non-isomorphic connected bipartite simple graphs are there with four vertices?
I got below 3.
Numerically my answer is valid. But is it logically valid?
graph-theory
$endgroup$
add a comment |
$begingroup$
How many non-isomorphic connected bipartite simple graphs are there with four vertices?
I got below 3.
Numerically my answer is valid. But is it logically valid?
graph-theory
$endgroup$
$begingroup$
What was your logic? You've not written how you reached here
$endgroup$
– Ankit Kumar
Dec 25 '18 at 6:11
$begingroup$
Looks correct if you don't care about which named node has which 'function'. For example, in your left example, there are 3 more isomorphic versions were B, C, and D take the 'central place' that A has in your example. Those are isomorphic, but depending on why you need to consider this problem, those might still count as different. See for example en.wikipedia.org/wiki/Cayley%27s_formula, which deals with 'labeled' trees, which is obviously different from the question of unlabled trees.
$endgroup$
– Ingix
Dec 25 '18 at 9:30
add a comment |
$begingroup$
How many non-isomorphic connected bipartite simple graphs are there with four vertices?
I got below 3.
Numerically my answer is valid. But is it logically valid?
graph-theory
$endgroup$
How many non-isomorphic connected bipartite simple graphs are there with four vertices?
I got below 3.
Numerically my answer is valid. But is it logically valid?
graph-theory
graph-theory
asked Dec 25 '18 at 5:43
user3767495user3767495
3888
3888
$begingroup$
What was your logic? You've not written how you reached here
$endgroup$
– Ankit Kumar
Dec 25 '18 at 6:11
$begingroup$
Looks correct if you don't care about which named node has which 'function'. For example, in your left example, there are 3 more isomorphic versions were B, C, and D take the 'central place' that A has in your example. Those are isomorphic, but depending on why you need to consider this problem, those might still count as different. See for example en.wikipedia.org/wiki/Cayley%27s_formula, which deals with 'labeled' trees, which is obviously different from the question of unlabled trees.
$endgroup$
– Ingix
Dec 25 '18 at 9:30
add a comment |
$begingroup$
What was your logic? You've not written how you reached here
$endgroup$
– Ankit Kumar
Dec 25 '18 at 6:11
$begingroup$
Looks correct if you don't care about which named node has which 'function'. For example, in your left example, there are 3 more isomorphic versions were B, C, and D take the 'central place' that A has in your example. Those are isomorphic, but depending on why you need to consider this problem, those might still count as different. See for example en.wikipedia.org/wiki/Cayley%27s_formula, which deals with 'labeled' trees, which is obviously different from the question of unlabled trees.
$endgroup$
– Ingix
Dec 25 '18 at 9:30
$begingroup$
What was your logic? You've not written how you reached here
$endgroup$
– Ankit Kumar
Dec 25 '18 at 6:11
$begingroup$
What was your logic? You've not written how you reached here
$endgroup$
– Ankit Kumar
Dec 25 '18 at 6:11
$begingroup$
Looks correct if you don't care about which named node has which 'function'. For example, in your left example, there are 3 more isomorphic versions were B, C, and D take the 'central place' that A has in your example. Those are isomorphic, but depending on why you need to consider this problem, those might still count as different. See for example en.wikipedia.org/wiki/Cayley%27s_formula, which deals with 'labeled' trees, which is obviously different from the question of unlabled trees.
$endgroup$
– Ingix
Dec 25 '18 at 9:30
$begingroup$
Looks correct if you don't care about which named node has which 'function'. For example, in your left example, there are 3 more isomorphic versions were B, C, and D take the 'central place' that A has in your example. Those are isomorphic, but depending on why you need to consider this problem, those might still count as different. See for example en.wikipedia.org/wiki/Cayley%27s_formula, which deals with 'labeled' trees, which is obviously different from the question of unlabled trees.
$endgroup$
– Ingix
Dec 25 '18 at 9:30
add a comment |
0
active
oldest
votes
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',
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
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3051869%2fnon-isomorphic-connected-bipartite-simple-graphs%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
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.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3051869%2fnon-isomorphic-connected-bipartite-simple-graphs%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
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
$begingroup$
What was your logic? You've not written how you reached here
$endgroup$
– Ankit Kumar
Dec 25 '18 at 6:11
$begingroup$
Looks correct if you don't care about which named node has which 'function'. For example, in your left example, there are 3 more isomorphic versions were B, C, and D take the 'central place' that A has in your example. Those are isomorphic, but depending on why you need to consider this problem, those might still count as different. See for example en.wikipedia.org/wiki/Cayley%27s_formula, which deals with 'labeled' trees, which is obviously different from the question of unlabled trees.
$endgroup$
– Ingix
Dec 25 '18 at 9:30