Finding truth value of each propositional variable.

  • Thread starter Thread starter sunny79
  • Start date Start date
  • Tags Tags
    Value Variable
Click For Summary
The discussion focuses on finding the truth values of propositional variables in the expression [p^(qVr)]^ ~r, assuming it is true. The initial approach involved substituting True for all variables, leading to a conclusion that p and q are True while r is False. However, it was pointed out that this method is flawed since the expression must hold true under the given conditions. The importance of ensuring both components in an "and" statement are true is emphasized, which simplifies the evaluation. The conversation highlights the need for careful consideration of logical structures when determining truth values.
sunny79
Messages
77
Reaction score
8
Homework Statement
Assume that the compound statement is true. Find the truth value of each propositional variable.
Relevant Equations
[p^(qVr)]^ ~r
Note:
^ represents and.
V represents or
~ represents not
T represents True
F represents False

My solution...

I started by substituting T in all variables...

[p^(qVr)]^ ~r
[T^(TVT)] ^ ~T
(T^T) ^ F
T^F
F
The answer is p = True q = True r = False
 
Physics news on Phys.org
sunny79 said:
I started by substituting T in all variables...
That is not a good start. All you are given is that [p^(qVr)]^ ~r = T !
 
sunny79 said:
Homework Statement: Assume that the compound statement is true. Find the truth value of each propositional variable.
Homework Equations: [p^(qVr)]^ ~r

Note:
^ represents and.
V represents or
~ represents not
T represents True
F represents False

My solution...

I started by substituting T in all variables...

[p^(qVr)]^ ~r
[T^(TVT)] ^ ~T
(T^T) ^ F
T^F
F
The answer is p = True q = True r = False
Notice in an /\ sentence, both components must be true. That simplifies it a bit.
 
  • Like
Likes sunny79
Giving it away, eh :wink:
 
  • Like
Likes WWGD
WWGD said:
Notice in an /\ sentence, both components must be true. That simplifies it a bit.

Gotcha! Thanks. :)
 
  • Like
Likes WWGD

Similar threads

  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 8 ·
Replies
8
Views
1K
  • · Replies 4 ·
Replies
4
Views
5K
  • · Replies 3 ·
Replies
3
Views
4K
  • · Replies 5 ·
Replies
5
Views
1K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 19 ·
Replies
19
Views
3K
  • · Replies 17 ·
Replies
17
Views
2K