Propositional logic and Boolean Logic Thread :cool:
Computer Science and ICT discussion, revision, exam and homework help.
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Re: Propositional logic and Boolean Logic Thread :cool:Sure(Original post by SoulfulBoy)
Anyone wanna help me with some truth tables?
(I'll try 
)
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Re: Propositional logic and Boolean Logic Thread :cool:(Original post by SoulfulBoy)
Anyone wanna help me with some truth tables? go on
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Re: Propositional logic and Boolean Logic Thread :cool:I don't understand quite well the 3rd and 5th columns.
http://imageshack.us/photo/my-images...1021200243.jpg
Last edited by SoulfulBoy; 21-10-2011 at 20:10. -
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Re: Propositional logic and Boolean Logic Thread :cool: -
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Re: Propositional logic and Boolean Logic Thread :cool:The third column is:(Original post by SoulfulBoy)
I don't understand quite well the 3rd and 5th columns.
http://imageshack.us/photo/my-images...1021200243.jpg
1. (NOT A and B)
This means when A is FALSE and B is TRUE, then the above statement is TRUE.
The fifth column is:
2. (A and NOT B)
This means when A is TRUE and B is FALSE, then the above statement is TRUE. -
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Re: Propositional logic and Boolean Logic Thread :cool:[IMG]
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Re: Propositional logic and Boolean Logic Thread :cool:Thanks for your reply.(Original post by gff)
The third column is:
1. (NOT A and B)
This means when A is FALSE and B is TRUE, then the above statement is TRUE.
The fifth column is:
2. (A and NOT B)
This means when A is TRUE and B is FALSE, then the above statement is TRUE.
Could you explain the point 1. more explicitly, please? I understand that NOT A is the opposite truth value of A but I don't actually get the third column.
Could you give me examples using actual sentences please?
And the same goes for the point 2.
I guess I am too thick
Cheers, Gff!
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Re: Propositional logic and Boolean Logic Thread :cool:They will serve me in a shop if I'm not drugged AND I'm over sixteen(Original post by SoulfulBoy)
Could you explain the point 1. more explicitly, please? I understand that NOT A is the opposite truth value of A but I don't actually get the third column.
Let's say A is me being drugged (so A is true means I am drugged)
And B is me being over sixteen (so if B is true it means I'm over sixteen)
They will serve me if I'm NOT drugged (so NOT A) and over sixteen (which is B)
So for them to serve me NOT A has to be true and B has to be true
If NOT A is true, it means A is false (if I'm not drugged then obviously the statement "I am drugged" is false)
So that means NOT A AND B is true when A is false and B is true
Hope this makes sense
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Re: Propositional logic and Boolean Logic Thread :cool:I think they have answered the question(Original post by SoulfulBoy)
I don't understand quite well the 3rd and 5th columns.
http://imageshack.us/photo/my-images...1021200243.jpg
http://www.youtube.com/watch?v=xlUFkMKSB3Y
Also if you have some time, this will be extremely helpful if you're stuck.Last edited by FinalMH; 21-10-2011 at 20:33. -
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Re: Propositional logic and Boolean Logic Thread :cool:This was what I needed!!!!!! I see it all clear now!!!(Original post by ElMoro)
They will serve me in a shop if I'm not drugged AND I'm over sixteen
Let's say A is me being drugged (so A is true means I am drugged)
And B is me being over sixteen (so if B is true it means I'm over sixteen)
They will serve me if I'm NOT drugged (so NOT A) and over sixteen (which is B)
So for them to serve me NOT A has to be true and B has to be true
If NOT A is true, it means A is false (if I'm not drugged then obviously the statement "I am drugged" is false)
So that means NOT A AND B is true when A is false and B is true
Hope this makes sense
Thank you, so much, sir!
I will give you some pos reps tomorrow
(I already spent those I had today )
I will contact you if I have more doubts.
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Re: Propositional logic and Boolean Logic Thread :cool:For the first point.(Original post by SoulfulBoy)
Thanks for your reply.
Could you explain the point 1. more explicitly, please? I understand that NOT A is the opposite truth value of A but I don't actually get the third column.
Could you give me examples using actual sentences please?
And the same goes for the point 2.
I guess I am too thick
Cheers, Gff!
Example:
I would buy a place on the Moon if they it isn't too expensive, and if I can see it with my telescope.
This can be turned into a propositional logic statement, i.e.
= Places on the Moon are expensive.
= I can see them with my telescope.
Then, the statement
= I'll buy a place on the Moon.
This being said, the conditions for to be true are 
.
This implies that
.
Now, you know that I wouldn't buy a place on the moon when is true and is true.
This means that is FALSE when 
.
What are the other possibilities when I wouldn't buy a place on the moon? -
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Re: Propositional logic and Boolean Logic Thread :cool:I will watch it, FinalMH.(Original post by FinalMH)
I think they have answered the question
http://www.youtube.com/watch?v=xlUFkMKSB3Y
Also if you have some time, this will be extremely helpful if you're stuck.
Thanks! -
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Re: Propositional logic and Boolean Logic Thread :cool:You would not buy a place on the moon when:(Original post by gff)
For the first point.
Example:
I would buy a place on the Moon if they it isn't too expensive, and if I can see it with my telescope.
This can be turned into a propositional logic statement, i.e.
= Places on the Moon are expensive.
= I can see them with my telescope.
Then, the statement = I'll buy a place on the Moon.
This being said, the conditions for to be true are .
This implies that.
Now, you know that I wouldn't buy a place on the moon when is true and is true.
This means that is FALSE when .
What are the other possibilities when I wouldn't buy a place on the moon?
1. Places on the moon are not expensive and you cannot see them with your telescope.
2. Places on the moon are expensive and you cannot see them with your telescope.
Is it okay? -
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Re: Propositional logic and Boolean Logic Thread :cool:Not strictly correct. A valid deduction would be(Original post by gff)
For the first point.
Example:
I would buy a place on the Moon if they it isn't too expensive, and if I can see it with my telescope.
This can be turned into a propositional logic statement, i.e.
= Places on the Moon are expensive.
= I can see them with my telescope.
Then, the statement = I'll buy a place on the Moon.
This being said, the conditions for to be true are .
This implies that.
. Consider that (strictly speaking) by your original proposition, doesn't imply anything about the truth values of or (only vice versa). Specifically, 
is vacuously true.
Last edited by Planto; 21-10-2011 at 20:59. -
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Re: Propositional logic and Boolean Logic Thread :cool:Yes, it looks okay.(Original post by SoulfulBoy)
You would not buy a place on the moon when:
1. Places on the moon are not expensive and you cannot see them with your telescope.
2. Places on the moon are expensive and you cannot see them with your telescope.
Is it okay? -
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Re: Propositional logic and Boolean Logic Thread :cool:[IMG](Original post by ElMoro)
They will serve me in a shop if I'm not drugged AND I'm over sixteen
Let's say A is me being drugged (so A is true means I am drugged)
And B is me being over sixteen (so if B is true it means I'm over sixteen)
They will serve me if I'm NOT drugged (so NOT A) and over sixteen (which is B)
So for them to serve me NOT A has to be true and B has to be true
If NOT A is true, it means A is false (if I'm not drugged then obviously the statement "I am drugged" is false)
So that means NOT A AND B is true when A is false and B is true
Hope this makes sense
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Is the table ok? Also I don't know how to approach A XOR B
(I'll try 
)
(I already spent those I had today 
