Show that the boolean formulas $[(p ∧ ¬q) ∨ q] ∧ [(¬q ∧ p) ∨ r] and (p ∧ ¬q) ∨ (r ∧ q)$...
$begingroup$
So far I got this:
$[(p ∧ ¬q) ∨ q] ∧ [(¬q ∧ p) ∨ r]$:
- $p∧ T ∧ [(¬q∧p) ∨ r]$
- $p∧ [(p∧¬q) ∨ r]$
- $p lor r$
$(p ∧ ¬q) ∨ (r ∧ q):$
$(p ∧ ¬q) ∨ (q ∧ r)$
$(p ∧( ¬q ∨ q)∧ r$
$p ∧ T ∧ r$
$p ∧ r$
propositional-calculus
$endgroup$
add a comment |
$begingroup$
So far I got this:
$[(p ∧ ¬q) ∨ q] ∧ [(¬q ∧ p) ∨ r]$:
- $p∧ T ∧ [(¬q∧p) ∨ r]$
- $p∧ [(p∧¬q) ∨ r]$
- $p lor r$
$(p ∧ ¬q) ∨ (r ∧ q):$
$(p ∧ ¬q) ∨ (q ∧ r)$
$(p ∧( ¬q ∨ q)∧ r$
$p ∧ T ∧ r$
$p ∧ r$
propositional-calculus
$endgroup$
1
$begingroup$
By commutativity of $land$, your first formula is equivalent to $[(plandneg q)lor q]land[(plandneg q)lor r]$ and your second formula is equivalent to $(plandneg q)lor(qland r)$. And these are equivalent by the distributive law.
$endgroup$
– Andreas Blass
Jan 24 at 0:11
$begingroup$
can you please explain a little more on how [(p ∧ ¬q) ∨ q] ∧ [(¬q ∧ p) ∨ r] =(p ∧ ¬q) ∨ (r ∧ q)
$endgroup$
– Derek Long
Jan 24 at 1:22
$begingroup$
[(p∧¬q) V q ] ∧(p∧¬q) v r ] under first formula?
$endgroup$
– Derek Long
Jan 24 at 1:30
$begingroup$
Unfortunately, I don't see a way to explain more. My comment already broke the argument into three steps, each applying only one of the laws of propositional logic --- two uses of the commutative law of $land$ and one use of the distributive law. I see no way to break it down any further.
$endgroup$
– Andreas Blass
Jan 24 at 11:30
$begingroup$
Thank you! its making a lot more sense!
$endgroup$
– Derek Long
Jan 24 at 16:29
add a comment |
$begingroup$
So far I got this:
$[(p ∧ ¬q) ∨ q] ∧ [(¬q ∧ p) ∨ r]$:
- $p∧ T ∧ [(¬q∧p) ∨ r]$
- $p∧ [(p∧¬q) ∨ r]$
- $p lor r$
$(p ∧ ¬q) ∨ (r ∧ q):$
$(p ∧ ¬q) ∨ (q ∧ r)$
$(p ∧( ¬q ∨ q)∧ r$
$p ∧ T ∧ r$
$p ∧ r$
propositional-calculus
$endgroup$
So far I got this:
$[(p ∧ ¬q) ∨ q] ∧ [(¬q ∧ p) ∨ r]$:
- $p∧ T ∧ [(¬q∧p) ∨ r]$
- $p∧ [(p∧¬q) ∨ r]$
- $p lor r$
$(p ∧ ¬q) ∨ (r ∧ q):$
$(p ∧ ¬q) ∨ (q ∧ r)$
$(p ∧( ¬q ∨ q)∧ r$
$p ∧ T ∧ r$
$p ∧ r$
propositional-calculus
propositional-calculus
edited Jan 24 at 2:19


Namaste
1
1
asked Jan 24 at 0:03
Derek LongDerek Long
115
115
1
$begingroup$
By commutativity of $land$, your first formula is equivalent to $[(plandneg q)lor q]land[(plandneg q)lor r]$ and your second formula is equivalent to $(plandneg q)lor(qland r)$. And these are equivalent by the distributive law.
$endgroup$
– Andreas Blass
Jan 24 at 0:11
$begingroup$
can you please explain a little more on how [(p ∧ ¬q) ∨ q] ∧ [(¬q ∧ p) ∨ r] =(p ∧ ¬q) ∨ (r ∧ q)
$endgroup$
– Derek Long
Jan 24 at 1:22
$begingroup$
[(p∧¬q) V q ] ∧(p∧¬q) v r ] under first formula?
$endgroup$
– Derek Long
Jan 24 at 1:30
$begingroup$
Unfortunately, I don't see a way to explain more. My comment already broke the argument into three steps, each applying only one of the laws of propositional logic --- two uses of the commutative law of $land$ and one use of the distributive law. I see no way to break it down any further.
$endgroup$
– Andreas Blass
Jan 24 at 11:30
$begingroup$
Thank you! its making a lot more sense!
$endgroup$
– Derek Long
Jan 24 at 16:29
add a comment |
1
$begingroup$
By commutativity of $land$, your first formula is equivalent to $[(plandneg q)lor q]land[(plandneg q)lor r]$ and your second formula is equivalent to $(plandneg q)lor(qland r)$. And these are equivalent by the distributive law.
$endgroup$
– Andreas Blass
Jan 24 at 0:11
$begingroup$
can you please explain a little more on how [(p ∧ ¬q) ∨ q] ∧ [(¬q ∧ p) ∨ r] =(p ∧ ¬q) ∨ (r ∧ q)
$endgroup$
– Derek Long
Jan 24 at 1:22
$begingroup$
[(p∧¬q) V q ] ∧(p∧¬q) v r ] under first formula?
$endgroup$
– Derek Long
Jan 24 at 1:30
$begingroup$
Unfortunately, I don't see a way to explain more. My comment already broke the argument into three steps, each applying only one of the laws of propositional logic --- two uses of the commutative law of $land$ and one use of the distributive law. I see no way to break it down any further.
$endgroup$
– Andreas Blass
Jan 24 at 11:30
$begingroup$
Thank you! its making a lot more sense!
$endgroup$
– Derek Long
Jan 24 at 16:29
1
1
$begingroup$
By commutativity of $land$, your first formula is equivalent to $[(plandneg q)lor q]land[(plandneg q)lor r]$ and your second formula is equivalent to $(plandneg q)lor(qland r)$. And these are equivalent by the distributive law.
$endgroup$
– Andreas Blass
Jan 24 at 0:11
$begingroup$
By commutativity of $land$, your first formula is equivalent to $[(plandneg q)lor q]land[(plandneg q)lor r]$ and your second formula is equivalent to $(plandneg q)lor(qland r)$. And these are equivalent by the distributive law.
$endgroup$
– Andreas Blass
Jan 24 at 0:11
$begingroup$
can you please explain a little more on how [(p ∧ ¬q) ∨ q] ∧ [(¬q ∧ p) ∨ r] =(p ∧ ¬q) ∨ (r ∧ q)
$endgroup$
– Derek Long
Jan 24 at 1:22
$begingroup$
can you please explain a little more on how [(p ∧ ¬q) ∨ q] ∧ [(¬q ∧ p) ∨ r] =(p ∧ ¬q) ∨ (r ∧ q)
$endgroup$
– Derek Long
Jan 24 at 1:22
$begingroup$
[(p∧¬q) V q ] ∧(p∧¬q) v r ] under first formula?
$endgroup$
– Derek Long
Jan 24 at 1:30
$begingroup$
[(p∧¬q) V q ] ∧(p∧¬q) v r ] under first formula?
$endgroup$
– Derek Long
Jan 24 at 1:30
$begingroup$
Unfortunately, I don't see a way to explain more. My comment already broke the argument into three steps, each applying only one of the laws of propositional logic --- two uses of the commutative law of $land$ and one use of the distributive law. I see no way to break it down any further.
$endgroup$
– Andreas Blass
Jan 24 at 11:30
$begingroup$
Unfortunately, I don't see a way to explain more. My comment already broke the argument into three steps, each applying only one of the laws of propositional logic --- two uses of the commutative law of $land$ and one use of the distributive law. I see no way to break it down any further.
$endgroup$
– Andreas Blass
Jan 24 at 11:30
$begingroup$
Thank you! its making a lot more sense!
$endgroup$
– Derek Long
Jan 24 at 16:29
$begingroup$
Thank you! its making a lot more sense!
$endgroup$
– Derek Long
Jan 24 at 16:29
add a comment |
1 Answer
1
active
oldest
votes
$begingroup$
You're not doing this right. You can't just move parentheses around like you do.
For example, for the first one, you go from $(p land neg q) lor q$ to $p land top$, but that must mean you went from $(p land neg q) lor q$ to $p land (neg q lor q)$ .... which is not right:
In general, $(p land q) lor r$ is not equivalent to $p land (q lor r)$
You are similarly moving parentheses for the second expression in a way that is not allowed. Think about it: what if this was an algebraic expression using numbers? It would be like going from $(3 + 4) cdot (5+6)$ to $3 + 4 cdot 5 + 6$ ... that's clearly not something you can do!
$endgroup$
$begingroup$
yea that makes sense, im just not sure where to begin.
$endgroup$
– Derek Long
Jan 24 at 1:05
$begingroup$
@DerekLong see Andreas' comment !
$endgroup$
– Bram28
Jan 24 at 1:17
add a comment |
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%2f3085259%2fshow-that-the-boolean-formulas-p-%25e2%2588%25a7-%25c2%25acq-%25e2%2588%25a8-q-%25e2%2588%25a7-%25c2%25acq-%25e2%2588%25a7-p-%25e2%2588%25a8-r-and-p-%25e2%2588%25a7-%25c2%25acq-%25e2%2588%25a8%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
$begingroup$
You're not doing this right. You can't just move parentheses around like you do.
For example, for the first one, you go from $(p land neg q) lor q$ to $p land top$, but that must mean you went from $(p land neg q) lor q$ to $p land (neg q lor q)$ .... which is not right:
In general, $(p land q) lor r$ is not equivalent to $p land (q lor r)$
You are similarly moving parentheses for the second expression in a way that is not allowed. Think about it: what if this was an algebraic expression using numbers? It would be like going from $(3 + 4) cdot (5+6)$ to $3 + 4 cdot 5 + 6$ ... that's clearly not something you can do!
$endgroup$
$begingroup$
yea that makes sense, im just not sure where to begin.
$endgroup$
– Derek Long
Jan 24 at 1:05
$begingroup$
@DerekLong see Andreas' comment !
$endgroup$
– Bram28
Jan 24 at 1:17
add a comment |
$begingroup$
You're not doing this right. You can't just move parentheses around like you do.
For example, for the first one, you go from $(p land neg q) lor q$ to $p land top$, but that must mean you went from $(p land neg q) lor q$ to $p land (neg q lor q)$ .... which is not right:
In general, $(p land q) lor r$ is not equivalent to $p land (q lor r)$
You are similarly moving parentheses for the second expression in a way that is not allowed. Think about it: what if this was an algebraic expression using numbers? It would be like going from $(3 + 4) cdot (5+6)$ to $3 + 4 cdot 5 + 6$ ... that's clearly not something you can do!
$endgroup$
$begingroup$
yea that makes sense, im just not sure where to begin.
$endgroup$
– Derek Long
Jan 24 at 1:05
$begingroup$
@DerekLong see Andreas' comment !
$endgroup$
– Bram28
Jan 24 at 1:17
add a comment |
$begingroup$
You're not doing this right. You can't just move parentheses around like you do.
For example, for the first one, you go from $(p land neg q) lor q$ to $p land top$, but that must mean you went from $(p land neg q) lor q$ to $p land (neg q lor q)$ .... which is not right:
In general, $(p land q) lor r$ is not equivalent to $p land (q lor r)$
You are similarly moving parentheses for the second expression in a way that is not allowed. Think about it: what if this was an algebraic expression using numbers? It would be like going from $(3 + 4) cdot (5+6)$ to $3 + 4 cdot 5 + 6$ ... that's clearly not something you can do!
$endgroup$
You're not doing this right. You can't just move parentheses around like you do.
For example, for the first one, you go from $(p land neg q) lor q$ to $p land top$, but that must mean you went from $(p land neg q) lor q$ to $p land (neg q lor q)$ .... which is not right:
In general, $(p land q) lor r$ is not equivalent to $p land (q lor r)$
You are similarly moving parentheses for the second expression in a way that is not allowed. Think about it: what if this was an algebraic expression using numbers? It would be like going from $(3 + 4) cdot (5+6)$ to $3 + 4 cdot 5 + 6$ ... that's clearly not something you can do!
edited Jan 24 at 0:32
answered Jan 24 at 0:20
Bram28Bram28
63.7k44793
63.7k44793
$begingroup$
yea that makes sense, im just not sure where to begin.
$endgroup$
– Derek Long
Jan 24 at 1:05
$begingroup$
@DerekLong see Andreas' comment !
$endgroup$
– Bram28
Jan 24 at 1:17
add a comment |
$begingroup$
yea that makes sense, im just not sure where to begin.
$endgroup$
– Derek Long
Jan 24 at 1:05
$begingroup$
@DerekLong see Andreas' comment !
$endgroup$
– Bram28
Jan 24 at 1:17
$begingroup$
yea that makes sense, im just not sure where to begin.
$endgroup$
– Derek Long
Jan 24 at 1:05
$begingroup$
yea that makes sense, im just not sure where to begin.
$endgroup$
– Derek Long
Jan 24 at 1:05
$begingroup$
@DerekLong see Andreas' comment !
$endgroup$
– Bram28
Jan 24 at 1:17
$begingroup$
@DerekLong see Andreas' comment !
$endgroup$
– Bram28
Jan 24 at 1:17
add a comment |
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%2f3085259%2fshow-that-the-boolean-formulas-p-%25e2%2588%25a7-%25c2%25acq-%25e2%2588%25a8-q-%25e2%2588%25a7-%25c2%25acq-%25e2%2588%25a7-p-%25e2%2588%25a8-r-and-p-%25e2%2588%25a7-%25c2%25acq-%25e2%2588%25a8%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
1
$begingroup$
By commutativity of $land$, your first formula is equivalent to $[(plandneg q)lor q]land[(plandneg q)lor r]$ and your second formula is equivalent to $(plandneg q)lor(qland r)$. And these are equivalent by the distributive law.
$endgroup$
– Andreas Blass
Jan 24 at 0:11
$begingroup$
can you please explain a little more on how [(p ∧ ¬q) ∨ q] ∧ [(¬q ∧ p) ∨ r] =(p ∧ ¬q) ∨ (r ∧ q)
$endgroup$
– Derek Long
Jan 24 at 1:22
$begingroup$
[(p∧¬q) V q ] ∧(p∧¬q) v r ] under first formula?
$endgroup$
– Derek Long
Jan 24 at 1:30
$begingroup$
Unfortunately, I don't see a way to explain more. My comment already broke the argument into three steps, each applying only one of the laws of propositional logic --- two uses of the commutative law of $land$ and one use of the distributive law. I see no way to break it down any further.
$endgroup$
– Andreas Blass
Jan 24 at 11:30
$begingroup$
Thank you! its making a lot more sense!
$endgroup$
– Derek Long
Jan 24 at 16:29