Verifying a proof regarding the duals of two equivalent compound propositions also being equivalent












1














I am aware that there are many previously asked questions regarding the proof that the duals of two equivalent compound propositions containing only logical operators ∨, ∧, and ¬ are also equivalent, although I have not yet been content with the solutions I have found.



If possible, I would like someone qualified to see if I am on the right track with my current proof of the above. Please note that I am only at a relatively basic level for proof-writing, although I wish to advance this whenever possible.



Below is a definition of the dual of a compound proposition containing only logical operators ∨, ∧, and ¬, found in Discrete Mathematics and Its Applications, 7th Edition, by Rosen, followed by the relevant theorem and current draft of my proof.




The dual of a compound proposition that contains only the
logical operators ∨, ∧, and ¬ is the compound proposition
obtained by replacing each ∨ by ∧, each ∧ by ∨, each T
by F, and each F by T. The dual of s is denoted by s∗.




 




Theorem:

The duals of two equivalent compound propositions are also equivalent.



Proof:

Let $s_0$, $s_n$ be two arbitrary compound propositions containing
only logical operators ∨, ∧, or ¬, such that $s_0$ $equiv$ $s_n$
after transforming $s_0$ with n logical equivalences containing
only logical operators ∨, ∧, or ¬.



Let $t_0$, $t_1$, $ldots$ , tn-1 be an ordered sequence of
n transformations using logical equivalences only containing the ∨, ∧,
or ¬ operators such that $t_i$($s_i$) = si+1, for 0 $leq$
i $leq$ n-1, where $s_i$, si+1 are compound propositions, and let
$s_0^*$, $s_1^*$, $ldots$ , $s_n^*$ be the
corresponding duals for $s_0$, $s_1$, $ldots$ , $s_n$, respectively.



We wish to find an ordered list of m transformations, $t_0^*$, $t_1^*$,
$ldots$ , tm-1$^*$ such that $t_i^*$($s_i^*$) =
si+1$^*$,
for 0 $leq$ i $leq$ m-1, where $s_i$,
si+1 are compound propositions.



Since every logical equivalence for a compound proposition containing only
the ∨, ∧, or ¬ operators has a dual equivalent, that is, a complementary
logical equivalence for the dual of the compound proposition, we let the
logical equivalence transformation $t_i^*$ be the dual equivalent of the
transformation $t_i$ when the transformation is performed on a compound
proposition, and otherwise the same transformation when performed on an
individual element,
for 0 $leq$ i $leq$ n-1.



Thus, $t_i^*$($s_i^*$) = si+1$^*$, for 0 $leq$ i $leq$ n-1,
is a valid ordered sequence of logical equivalence transformations, and $s_0^*$
$equiv$ $s_n^*$. Since $s_0^*$ and $s_n^*$ were chosen to be arbitrary,
true for all such.



End of proof.




I feel that the first statement in last paragraph of my proof is not explicit enough, although I am not currently able to think of what is additionally needed.



Please help if possible. Thank you!










share|cite|improve this question









New contributor




christophercrary is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.




















  • Yes, this is correct.
    – Berci
    Dec 26 '18 at 22:53
















1














I am aware that there are many previously asked questions regarding the proof that the duals of two equivalent compound propositions containing only logical operators ∨, ∧, and ¬ are also equivalent, although I have not yet been content with the solutions I have found.



If possible, I would like someone qualified to see if I am on the right track with my current proof of the above. Please note that I am only at a relatively basic level for proof-writing, although I wish to advance this whenever possible.



Below is a definition of the dual of a compound proposition containing only logical operators ∨, ∧, and ¬, found in Discrete Mathematics and Its Applications, 7th Edition, by Rosen, followed by the relevant theorem and current draft of my proof.




The dual of a compound proposition that contains only the
logical operators ∨, ∧, and ¬ is the compound proposition
obtained by replacing each ∨ by ∧, each ∧ by ∨, each T
by F, and each F by T. The dual of s is denoted by s∗.




 




Theorem:

The duals of two equivalent compound propositions are also equivalent.



Proof:

Let $s_0$, $s_n$ be two arbitrary compound propositions containing
only logical operators ∨, ∧, or ¬, such that $s_0$ $equiv$ $s_n$
after transforming $s_0$ with n logical equivalences containing
only logical operators ∨, ∧, or ¬.



Let $t_0$, $t_1$, $ldots$ , tn-1 be an ordered sequence of
n transformations using logical equivalences only containing the ∨, ∧,
or ¬ operators such that $t_i$($s_i$) = si+1, for 0 $leq$
i $leq$ n-1, where $s_i$, si+1 are compound propositions, and let
$s_0^*$, $s_1^*$, $ldots$ , $s_n^*$ be the
corresponding duals for $s_0$, $s_1$, $ldots$ , $s_n$, respectively.



We wish to find an ordered list of m transformations, $t_0^*$, $t_1^*$,
$ldots$ , tm-1$^*$ such that $t_i^*$($s_i^*$) =
si+1$^*$,
for 0 $leq$ i $leq$ m-1, where $s_i$,
si+1 are compound propositions.



Since every logical equivalence for a compound proposition containing only
the ∨, ∧, or ¬ operators has a dual equivalent, that is, a complementary
logical equivalence for the dual of the compound proposition, we let the
logical equivalence transformation $t_i^*$ be the dual equivalent of the
transformation $t_i$ when the transformation is performed on a compound
proposition, and otherwise the same transformation when performed on an
individual element,
for 0 $leq$ i $leq$ n-1.



Thus, $t_i^*$($s_i^*$) = si+1$^*$, for 0 $leq$ i $leq$ n-1,
is a valid ordered sequence of logical equivalence transformations, and $s_0^*$
$equiv$ $s_n^*$. Since $s_0^*$ and $s_n^*$ were chosen to be arbitrary,
true for all such.



End of proof.




I feel that the first statement in last paragraph of my proof is not explicit enough, although I am not currently able to think of what is additionally needed.



Please help if possible. Thank you!










share|cite|improve this question









New contributor




christophercrary is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.




















  • Yes, this is correct.
    – Berci
    Dec 26 '18 at 22:53














1












1








1







I am aware that there are many previously asked questions regarding the proof that the duals of two equivalent compound propositions containing only logical operators ∨, ∧, and ¬ are also equivalent, although I have not yet been content with the solutions I have found.



If possible, I would like someone qualified to see if I am on the right track with my current proof of the above. Please note that I am only at a relatively basic level for proof-writing, although I wish to advance this whenever possible.



Below is a definition of the dual of a compound proposition containing only logical operators ∨, ∧, and ¬, found in Discrete Mathematics and Its Applications, 7th Edition, by Rosen, followed by the relevant theorem and current draft of my proof.




The dual of a compound proposition that contains only the
logical operators ∨, ∧, and ¬ is the compound proposition
obtained by replacing each ∨ by ∧, each ∧ by ∨, each T
by F, and each F by T. The dual of s is denoted by s∗.




 




Theorem:

The duals of two equivalent compound propositions are also equivalent.



Proof:

Let $s_0$, $s_n$ be two arbitrary compound propositions containing
only logical operators ∨, ∧, or ¬, such that $s_0$ $equiv$ $s_n$
after transforming $s_0$ with n logical equivalences containing
only logical operators ∨, ∧, or ¬.



Let $t_0$, $t_1$, $ldots$ , tn-1 be an ordered sequence of
n transformations using logical equivalences only containing the ∨, ∧,
or ¬ operators such that $t_i$($s_i$) = si+1, for 0 $leq$
i $leq$ n-1, where $s_i$, si+1 are compound propositions, and let
$s_0^*$, $s_1^*$, $ldots$ , $s_n^*$ be the
corresponding duals for $s_0$, $s_1$, $ldots$ , $s_n$, respectively.



We wish to find an ordered list of m transformations, $t_0^*$, $t_1^*$,
$ldots$ , tm-1$^*$ such that $t_i^*$($s_i^*$) =
si+1$^*$,
for 0 $leq$ i $leq$ m-1, where $s_i$,
si+1 are compound propositions.



Since every logical equivalence for a compound proposition containing only
the ∨, ∧, or ¬ operators has a dual equivalent, that is, a complementary
logical equivalence for the dual of the compound proposition, we let the
logical equivalence transformation $t_i^*$ be the dual equivalent of the
transformation $t_i$ when the transformation is performed on a compound
proposition, and otherwise the same transformation when performed on an
individual element,
for 0 $leq$ i $leq$ n-1.



Thus, $t_i^*$($s_i^*$) = si+1$^*$, for 0 $leq$ i $leq$ n-1,
is a valid ordered sequence of logical equivalence transformations, and $s_0^*$
$equiv$ $s_n^*$. Since $s_0^*$ and $s_n^*$ were chosen to be arbitrary,
true for all such.



End of proof.




I feel that the first statement in last paragraph of my proof is not explicit enough, although I am not currently able to think of what is additionally needed.



Please help if possible. Thank you!










share|cite|improve this question









New contributor




christophercrary is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.











I am aware that there are many previously asked questions regarding the proof that the duals of two equivalent compound propositions containing only logical operators ∨, ∧, and ¬ are also equivalent, although I have not yet been content with the solutions I have found.



If possible, I would like someone qualified to see if I am on the right track with my current proof of the above. Please note that I am only at a relatively basic level for proof-writing, although I wish to advance this whenever possible.



Below is a definition of the dual of a compound proposition containing only logical operators ∨, ∧, and ¬, found in Discrete Mathematics and Its Applications, 7th Edition, by Rosen, followed by the relevant theorem and current draft of my proof.




The dual of a compound proposition that contains only the
logical operators ∨, ∧, and ¬ is the compound proposition
obtained by replacing each ∨ by ∧, each ∧ by ∨, each T
by F, and each F by T. The dual of s is denoted by s∗.




 




Theorem:

The duals of two equivalent compound propositions are also equivalent.



Proof:

Let $s_0$, $s_n$ be two arbitrary compound propositions containing
only logical operators ∨, ∧, or ¬, such that $s_0$ $equiv$ $s_n$
after transforming $s_0$ with n logical equivalences containing
only logical operators ∨, ∧, or ¬.



Let $t_0$, $t_1$, $ldots$ , tn-1 be an ordered sequence of
n transformations using logical equivalences only containing the ∨, ∧,
or ¬ operators such that $t_i$($s_i$) = si+1, for 0 $leq$
i $leq$ n-1, where $s_i$, si+1 are compound propositions, and let
$s_0^*$, $s_1^*$, $ldots$ , $s_n^*$ be the
corresponding duals for $s_0$, $s_1$, $ldots$ , $s_n$, respectively.



We wish to find an ordered list of m transformations, $t_0^*$, $t_1^*$,
$ldots$ , tm-1$^*$ such that $t_i^*$($s_i^*$) =
si+1$^*$,
for 0 $leq$ i $leq$ m-1, where $s_i$,
si+1 are compound propositions.



Since every logical equivalence for a compound proposition containing only
the ∨, ∧, or ¬ operators has a dual equivalent, that is, a complementary
logical equivalence for the dual of the compound proposition, we let the
logical equivalence transformation $t_i^*$ be the dual equivalent of the
transformation $t_i$ when the transformation is performed on a compound
proposition, and otherwise the same transformation when performed on an
individual element,
for 0 $leq$ i $leq$ n-1.



Thus, $t_i^*$($s_i^*$) = si+1$^*$, for 0 $leq$ i $leq$ n-1,
is a valid ordered sequence of logical equivalence transformations, and $s_0^*$
$equiv$ $s_n^*$. Since $s_0^*$ and $s_n^*$ were chosen to be arbitrary,
true for all such.



End of proof.




I feel that the first statement in last paragraph of my proof is not explicit enough, although I am not currently able to think of what is additionally needed.



Please help if possible. Thank you!







discrete-mathematics proof-verification logic proof-writing






share|cite|improve this question









New contributor




christophercrary is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.











share|cite|improve this question









New contributor




christophercrary is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.









share|cite|improve this question




share|cite|improve this question








edited Dec 26 '18 at 22:45





















New contributor




christophercrary is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.









asked Dec 26 '18 at 22:36









christophercrary

63




63




New contributor




christophercrary is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.





New contributor





christophercrary is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.






christophercrary is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.












  • Yes, this is correct.
    – Berci
    Dec 26 '18 at 22:53


















  • Yes, this is correct.
    – Berci
    Dec 26 '18 at 22:53
















Yes, this is correct.
– Berci
Dec 26 '18 at 22:53




Yes, this is correct.
– Berci
Dec 26 '18 at 22:53















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
});


}
});






christophercrary is a new contributor. Be nice, and check out our Code of Conduct.










draft saved

draft discarded


















StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3053384%2fverifying-a-proof-regarding-the-duals-of-two-equivalent-compound-propositions-al%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown






























active

oldest

votes













active

oldest

votes









active

oldest

votes






active

oldest

votes








christophercrary is a new contributor. Be nice, and check out our Code of Conduct.










draft saved

draft discarded


















christophercrary is a new contributor. Be nice, and check out our Code of Conduct.













christophercrary is a new contributor. Be nice, and check out our Code of Conduct.












christophercrary is a new contributor. Be nice, and check out our Code of Conduct.
















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%2f3053384%2fverifying-a-proof-regarding-the-duals-of-two-equivalent-compound-propositions-al%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

Human spaceflight

Can not write log (Is /dev/pts mounted?) - openpty in Ubuntu-on-Windows?

張江高科駅