Compound Proposition Simplification

  • Context: MHB 
  • Thread starter Thread starter User40405
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Discussion Overview

The discussion revolves around the simplification of a compound proposition using logical equivalences, specifically focusing on the expression $[(p \vee q) \wedge \neg p] \to q$. Participants seek assistance in understanding the simplification process and the application of logical laws.

Discussion Character

  • Homework-related, Technical explanation, Exploratory

Main Points Raised

  • One participant expresses difficulty in simplifying the compound proposition and requests guidance on the process.
  • Another participant states that $a \to b$ is equivalent to $\neg a \vee b$ and applies this to the expression, suggesting it can be rewritten as $\neg [(p \vee q) \wedge \neg p] \vee q$.
  • A different participant reiterates the same equivalence and expresses gratitude for the help received.
  • One participant mentions reaching a point in the simplification but struggles with the expression $(p \vee q)$ and questions how to proceed.
  • Another participant suggests using the distributive law to simplify the expression, providing a specific equivalence involving $q \wedge \neg p$.
  • One participant notes a lack of instruction on the topic from their professor and seeks help with the simplification.
  • Another participant interprets the logical expression and concludes that if "p is true OR q is true" AND "p is NOT true," then it follows that q must be true.

Areas of Agreement / Disagreement

Participants express varying levels of understanding and approaches to the problem, with no consensus on the simplification process or the final form of the expression. Multiple competing views and methods are presented without resolution.

Contextual Notes

Some participants reference logical equivalences and laws without fully explaining their application, leading to potential gaps in understanding for those less familiar with the concepts. There is also an indication that not all participants have been taught the necessary theory to simplify the proposition effectively.

Who May Find This Useful

This discussion may be useful for students learning about logical equivalences and simplification of compound propositions, particularly those seeking help with homework or theoretical understanding in logic.

User40405
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Hi all

I need to complete this question for an assignment, but I cannot seem to understand how to simplify the compound proposition with logical equivalences. If anyone here understands how to complete this question, please could you show me how, as it would be greatly appreciated. Thank you.

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You know that $a \to b$ is equivalent to $\neg a \vee b$

Therefore $[(p \vee q) \wedge \neg p] \to q$ is equivalent to $\neg [(p \vee q) \wedge \neg p] \vee q$

Now you can simplify the last expression.
 
steenis said:
You know that $a \to b$ is equivalent to $\neg a \vee b$

Therefore $[(p \vee q) \wedge \neg p] \to q$ is equivalent to $\neg [(p \vee q) \wedge \neg p] \vee q$

Now you can simplify the last expression.

Thank you so so much!

I have been checking guides the entire day and yesterday. I can now get to where you got with it, but I cannot simplify the last expression (pvq). I do not know how to change this and get the simplified form.

- - - Updated - - -

Because (pvq) is equivalent to (qvp). But how does that help me?
 
Or use the distributive law in the first block:
$$(p\vee q)\wedge\neg p\ \equiv\ (p\wedge\neg p)\vee(q\wedge\neg p)\ \equiv\ q\wedge\neg p.$$
 
I. study the theory

II. use $\neg (a \wedge b)$ is equivalent with $\neg a \vee \neg b$
 
Hey guys I have the same problem given by our professor but we weren't even taught anything that we can use with simplifying the given compound proposition.

I was hoping someone can help and show how to simplify that given, it would be a really great help.
 
I don't know what "study the theory" or "use" mean here. I do know that you have "p is true OR q is true" AND "p is NOT true". It follows that q must be true.
 

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