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From: Jimmy <jim...@an...> - 2011-08-22 00:00:27
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Hi, I've recently come across a problem where I'd like to replace some BDD variables with some formulae (for example, replace variable 0 with "1 OR 2" and variable 2 with "4 OR 7"), and it looks like bdd_veccompose is the function I want to use. However I can't seem to work out how to use it. It takes a bddPair, and from what I can understand a bddPair is strictly from variables to variables, not from variables to arbitrary BDDs. I tried playing around with a trivial example to see if I could ignore this, and add a pair entry from bdd_ithvar(0) to bdd_or(bdd_ithvar(1),bdd_ithvar(2)), but this complains about unknown variables. The documentation of bdd_setpairs also seems unclear to me, taking integers (rather than BDDs) for arguments, but the description indicating that the arrays can contain BDDs. Am I on the right track, and if not, what should I be using instead? The alternative that comes to mind would be replacing the variables with fresh ones and then doing a series of bdd_compose calls, but this doesn't sound particularly good. Thanks, Jimmy |