Re: [Javabdd-devel] Retrieving a set from a BDD

[Wassim M. <wm...@au...>]

Hi John,

(Thank you for the quick response)

If I keep "itemsSet1" and "itemsSet2" around, would I be achieving any =20
compression?

It seems to me that set1 and set2 will stored in 2 different places =20
now, since I would have:

1) set1 and set2 represented by the BDDs referenced by "itemsSet1" and =20
"itemsSet2" (no compression is achieved here).

AND

2) set1 and set2 stored (potentially compressed) in poolOfSets.

Note that in order to keep "itemsSet1" and "itemsSet2" around, they =20
cannot be consumed, i.e., I must pass their clone when adding them to =20
"poolOfSets":
...
poolOfSets.andWith(itemsSet1.id());
poolOfSets.andWith(itemsSet2.id());
...


Finally, in order to verify my understanding above, I freed =20
"poolOfSets" then tried to retrieve set1 and set2 using "itemsSet1" =20
and "itemsSet2", the test was successful (please see last 3 statements):

BDDFactory B;
B =3D BDDFactory.init(1000, 1000);
B.setVarNum(500);

// pool of items
BDD [] items =3D new BDD[100];
for (int i =3D 0; i < 100; i++)
{
=09items[i] =3D B.ithVar(i);
}

// set 1
BDD itemsSet1 =3D B.zero();
itemsSet1.orWith(items[0].id());
itemsSet1.orWith(items[1].id());
itemsSet1.orWith(items[2].id());
itemsSet1.orWith(items[3].id());
System.out.println("itemsSet1 " + itemsSet1);
System.out.println("count " + itemsSet1.nodeCount());

// set 2
BDD itemsSet2 =3D B.zero();
itemsSet2.orWith(items[10].id());
itemsSet2.orWith(items[11].id());
itemsSet2.orWith(items[2].id());
itemsSet2.orWith(items[3].id());
System.out.println("itemsSet2 " + itemsSet2);
System.out.println("count " + itemsSet2.nodeCount());

// pool of sets
BDD poolOfSets;
poolOfSets =3D B.one();
poolOfSets.andWith(itemsSet1.id());
poolOfSets.andWith(itemsSet2.id());
System.out.println("poolOfSets " + poolOfSets);
System.out.println("count " + poolOfSets.nodeCount());

// retrieve set1 and set2
System.out.println("itemsSet1 " + itemsSet1); // got set1 successfully
System.out.println("itemsSet1 " + itemsSet2); // got set2 successfully

// retrieve set1 and set2 after freeing poolOfSets
poolOfSets.free();  // <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
System.out.println("itemsSet1 " + itemsSet1); // got set1 successfully
System.out.println("itemsSet1 " + itemsSet2); // got set2 successfully

To recap, my goal is:
1) To be able to free "itemsSet1" and "itemsSet2" right after I store =20
set1 and set2 in "poolOfSets"

2) Retrieve set1 and set2 from "poolOfSets", which maintain them in =20
compressed form.

Thank you for your help
Wes Masri


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