The output would be Logical Implications: A => B and B => A.

  • Thread starter Thread starter John112
  • Start date Start date
  • Tags Tags
    implication
Click For Summary

Homework Help Overview

The discussion revolves around logical implications involving two expressions, A and B, defined as A: (p => ~q) ^ (p v q) and B: ~p v q. Participants are exploring whether A implies B and whether B implies A, utilizing truth tables to analyze these relationships.

Discussion Character

  • Exploratory, Assumption checking, Mathematical reasoning

Approaches and Questions Raised

  • Participants are examining the implications A => B and B => A through truth tables and questioning the conditions under which these implications hold true. There is a focus on whether the implications need to be tautologies and the significance of truth values in the context of logical implications.

Discussion Status

The discussion is ongoing, with participants providing insights into the nature of implications and truth values. Some have suggested creating a truth table to clarify the relationships between A and B, while others are questioning the necessity of tautologies for implications.

Contextual Notes

There is a repeated emphasis on the truth values of A and B, particularly in relation to when the implications are considered true or false. Participants are also reflecting on the structure of truth tables and their relevance to logical reasoning.

John112
Messages
19
Reaction score
0
A: (p => ~q) ^ (p v q)
B: ~p v q

does A => B (A implies B) ?
does B => A ( B implies A) ?

I did the truth tables for each:

A => B:
http://www4c.wolframalpha.com/input/?i=((p+=>+NOT+q)+AND+(p+OR+q))+=>+(NOT+p+OR+q)

B => A:
http://www.wolframalpha.com/input/?i=(NOT+p+OR+q)+=>+((p+=>+NOT+q)+AND+(p+OR+q))+.

for A to logically imply B or for B to logically imply A, does it need to be a tautology? Meaning if A=> B or B=> A , on the truth tables should it be All Ts? or should the final column of the truh table of A=> B or B => A resemble the truth table of an implication?
 
Last edited:
Physics news on Phys.org
John112 said:
A: (p => ~q) ^ (p v q)
B: ~p v q

does A => B (A implies B) ?
does B => A ( B implies A) ?

I did the truth tables for each:

A => B:
http://www4c.wolframalpha.com/input/?i=((p+=>+NOT+q)+AND+(p+OR+q))+=>+(NOT+p+OR+q)

B => A:
http://www.wolframalpha.com/input/?i=(NOT+p+OR+q)+=>+((p+=>+NOT+q)+AND+(p+OR+q))+.

for A to logically imply B or for B to logically imply A, does it need to be a tautology? Meaning if A=> B or B=> A , on the truth tables should it be All Ts? or should the final column of the truh table of A=> B or B => A resemble the truth table of an implication?

For the implication A => B, the only False you can have is when A is True and B is False. For all other combinations of truth values for A and B, the implication is considered to be True.
For the implication B => A, the only False you can have is when B is True and A is False. For all other combinations of truth values for B and A, the implication is considered to be True.
 
Mark44 said:
For the implication A => B, the only False you can have is when A is True and B is False. For all other combinations of truth values for A and B, the implication is considered to be True.
For the implication B => A, the only False you can have is when B is True and A is False. For all other combinations of truth values for B and A, the implication is considered to be True.

So does A logically imply B? or does B logically implies A?
 
Make a truth table with five columns, one each for p, q, (p => ~q) ^ (p v q), ~p v q, and ((p => ~q) ^ (p v q)) => ~p v q. You can say that A => B if the only false value you get in the fifth column is in the row where there's a T in the third column and an F in the fourth column.

Similar idea for B => A.
 

Similar threads

  • · Replies 22 ·
Replies
22
Views
4K
Replies
2
Views
1K
  • · Replies 2 ·
Replies
2
Views
4K
  • · Replies 9 ·
Replies
9
Views
3K
  • · Replies 20 ·
Replies
20
Views
4K
Replies
5
Views
3K
  • · Replies 7 ·
Replies
7
Views
5K
Replies
2
Views
2K
Replies
1
Views
2K
  • · Replies 7 ·
Replies
7
Views
4K