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strange booleanconvert behavior?

  • To: mathgroup at smc.vnet.net
  • Subject: [mg127231] strange booleanconvert behavior?
  • From: Francisco Gutierrez <fgutiers2002 at yahoo.com>
  • Date: Tue, 10 Jul 2012 00:42:11 -0400 (EDT)
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  • Reply-to: Francisco Gutierrez <fgutiers2002 at yahoo.com>

Dear Group:
Say I have the following expression:
num1={{a,b,c,d},{a,b,c,e},{a,b,c,f},{a,b,c,g},{a,b,c,h},{a,b,c,i},{a,b,c,j},{a,b,c,k},{a,b,c,l},{a,b,c,m},{a,b,c,n}}

I transform it into a logical expression:
n=
um2=Apply[Or,Apply[And,#]&/@num1]
 
I want to simplify this to a CNF, and the obvious function to use is Boolean Convert. Suppose I apply it to NINE elements of num2:
BooleanConvert[Take[num2,9],"CNF"]
The output is
a&&b&&c&&(d||e||f||g||h||i||j||k||l)

It works perfectly well! 

However, if I apply BooleanConvert to the whole expression I get back a bunch of crap. Also if I apply it to 10 elements of num2. 
In sum, it appears that BooleanConvert only works well for 9 expressions or less. Tried this with other two examples, and found
exactly the same result.

All this in Mathematica 8

Can somebody help me?
Francisco



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