Bucc's Logic Thread

[OoA Rob]

Rules:
Either K or H, or both, happening
Either R or V, but not both happen
If A is happening, so is R.?
V and K are either both happening or neither is
If H happens then so are A and K

You can replace happening with chating.


if K is picked then you can not have R
if A is picked you must have R then you can not use K if there is A or R
rule,If H happens then so does A and K
if A and K happen then R and V happen
rule, Either R or V, but not both
therefore,H can not happen
if H can not happen then we must pick K
rule,if K happens then V happens
rule, Either R or V, but not both happen
therefore, R can not happen
rule, if A happens then R happens
rule, Either R or V, but not both happen
therefore, V must happen

Conclusion, H, R, and A can not happen. There are only 2 rules saying you must pick 1 name, making 2 people must be picked.
Only K and V work.

let me know if how well this makes sense.

for Bucc's post, I will handle later.

[|MP|Buccaneer]

Five friends have access to a chat room.  Is it possible to determine who is chatting if the following info is known? Either Kevin or Heather, or both, are chatting.  Either Randy or Vijay, but not both. are chatting.  If Abby is chatting, so is Randy.  Vijay and Kevin are either both chatting or neither is.  If Heather is chatting then so are Abby and Kevin.  Explain Reasoning.

if R not V
if V not R (doesn't need to be here)
if A then R
if V then K
if not V then not K
if H then A and K

Given R or V ; K and/or H (K, H, R, V, A)

First R
R
Not V
Not K
Not H
A is not resolvable (bad wording in the problem)

Conclusion: Can't be R because no K or H

Second V
V
Not R
Not A
K
Not H

Conslusion: Could be V and K, Fits all arguments

Third K
K
V
Not R
Not A
Not H

Conclusion: Could still be K and V.

Fourth H
H
A
K
V
Not R
R

Conclusion: invalid.

Fifth K and H
K
H
A
R
V
Not V

Conclusion: Invalid.

Final Conclusion: From that statement only V and K could be chatting together.  Vijay and Kevin.

If anyone wants to see the complete work, let me know.

[jn.loudnotes]

Ah Bucc you're right.  I misread the statement about Abby and Randy.  Abby can't be chatting.  

Interesting how we got the same answer (well, I would have if I hadn't screwed that one statement) but with very different ways to go about it.

[|MP|Buccaneer]

Doesn't surprise me at all Loudnotes.

I used shorthand, and just a very simple model to run the proof.  it works really well for math and computer programming too.

But that is by no means the only way to do it.  Logic is a disapline, as I've said, but it's also one that comes pretty naturally to, for lack of a better word, geeks.  Almost everyone here (there are some noted exceptions, and i'm not talking about bondo) has a basic understanding of logic.  How one thing leads to another.  People usually get tripped up because they don't know the major traps (or don't care).  Things like letting opinions in, or just linking two things that aren't.  But that's why there is debate.

Funny, whoever that new account was that posted it, deleted it too.  Maybe they will come back and let me know if that was an intentional typo in the problem, or if it was meant that way to make it easier to solve.