Re: [Hol-info] prove a goal in HOL4

2010-04-11 Thread liy_liu
Dear Jeremy,

I really appreciate your reply. However, the following sentence in my
question email is not my conclusion.

 Here, a and c are independant, also b and c are independant.
 However,  a depends b.

It is the assumption. As I wrote in the goal,
(indep bern a c) /\ (indep bern b c) means a and c are independant,
also b and c are independant, and a depends b; With this assumption,
I tried to prove
(prob bern (a INTER b INTER c) = prob bern (a INTER b) * prob bern c)`;

I think it doesn't contradict with the case that a, b, c are
independant, since prob bern (a INTER b) = prob bern a * prob bern b
in this case. And prob bern (a INTER b INTER c) = prob bern a * prob
bern b * prob bern c is true.

---
For sure, your example is very instructive, though events A, B, C are
independant there and this is not the case that I wanted to prove.

I'm not sure if I got your point or not. If not, please give me some
more explanation.

Thanks again!

Liya

Quoting Jeremy Dawson jer...@rsise.anu.edu.au:


 liy_...@encs.concordia.ca wrote:
 I have to prove a goal in HOL4 as following:

 g `!a b c. (indep bern a c) /\ (indep bern b c) ==
   (a IN events bern) /\ (b IN events bern) /\ (c IN events bern) /\
   (prob bern (a INTER b INTER c) = prob bern (a INTER b) * prob  
   bern c)`;

 Here, a and c are independant, also b and c are independant.
 However,  a depends b.

 Could anybody give me some hints? I really appreciate!

 Regards,
 Liya

 I can't guess what bern and events mean, but if prob and indep have a
 usual meaning, then it's not true.

 eg let 3 coins, X, Y, Z be tossed independently.

 Let event A be coins X and Y fall the same way

 Let event B be coins X and Z fall the same way

 Let event C be coins Z and Y fall the same way

 Then each two of the three events A,B,C are independent.  But A  B is
 not independent of C (which is what, I understand, the last line of
 your conclusion says)

 Regards,

 Jeremy




- End forwarded message -



--
Download Intel#174; Parallel Studio Eval
Try the new software tools for yourself. Speed compiling, find bugs
proactively, and fine-tune applications for parallel performance.
See why Intel Parallel Studio got high marks during beta.
http://p.sf.net/sfu/intel-sw-dev
___
hol-info mailing list
hol-info@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/hol-info


[Hol-info] prove a goal in HOL4

2010-04-07 Thread liy_liu
I have to prove a goal in HOL4 as following:

g `!a b c. (indep bern a c) /\ (indep bern b c) ==
   (a IN events bern) /\ (b IN events bern) /\ (c IN events bern) /\
   (prob bern (a INTER b INTER c) = prob bern (a INTER b) * prob bern c)`;

Here, a and c are independant, also b and c are independant. However,  
a depends b.

Could anybody give me some hints? I really appreciate!

Regards,
Liya


--
Download Intel#174; Parallel Studio Eval
Try the new software tools for yourself. Speed compiling, find bugs
proactively, and fine-tune applications for parallel performance.
See why Intel Parallel Studio got high marks during beta.
http://p.sf.net/sfu/intel-sw-dev
___
hol-info mailing list
hol-info@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/hol-info


Re: [Hol-info] prove a goal in HOL4

2010-04-07 Thread Jeremy Dawson

liy_...@encs.concordia.ca wrote:
 I have to prove a goal in HOL4 as following:

 g `!a b c. (indep bern a c) /\ (indep bern b c) ==
(a IN events bern) /\ (b IN events bern) /\ (c IN events bern) /\
(prob bern (a INTER b INTER c) = prob bern (a INTER b) * prob bern c)`;

 Here, a and c are independant, also b and c are independant. However,  
 a depends b.

 Could anybody give me some hints? I really appreciate!

 Regards,
 Liya
   
I can't guess what bern and events mean, but if prob and indep have a 
usual meaning, then it's not true.

eg let 3 coins, X, Y, Z be tossed independently.

Let event A be coins X and Y fall the same way

Let event B be coins X and Z fall the same way

Let event C be coins Z and Y fall the same way

Then each two of the three events A,B,C are independent.  But A  B is 
not independent of C (which is what, I understand, the last line of your 
conclusion says)

Regards,

Jeremy


--
Download Intel#174; Parallel Studio Eval
Try the new software tools for yourself. Speed compiling, find bugs
proactively, and fine-tune applications for parallel performance.
See why Intel Parallel Studio got high marks during beta.
http://p.sf.net/sfu/intel-sw-dev
___
hol-info mailing list
hol-info@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/hol-info