public void MakeNot()
{
var obdd = new OBDD();
var a = obdd.MakeLiteral(0);
var b = obdd.MakeLiteral(1);
Assert.IsNotNull(a);
Assert.IsNotNull(b);
Assert.AreNotEqual(a, b);
var na = obdd.MakeNot(a);
var nb = obdd.MakeNot(b);
Assert.IsNotNull(na);
Assert.IsNotNull(nb);
Assert.AreNotEqual(na, nb);
Assert.AreNotEqual(a, na);
Assert.AreNotEqual(b, nb);
var nna = obdd.MakeNot(na);
var nnb = obdd.MakeNot(nb);
Assert.IsNotNull(nna);
Assert.IsNotNull(nnb);
Assert.AreNotEqual(nna, nnb);
// double negation cancels out
Assert.AreEqual(a, nna);
Assert.AreEqual(b, nnb);
}
public void MakeLiteral()
{
var obdd = new OBDD();
var a = obdd.MakeLiteral(0);
var b = obdd.MakeLiteral(1);
var c = obdd.MakeLiteral(2);
Assert.IsNotNull(a);
Assert.IsNotNull(b);
Assert.IsNotNull(c);
Assert.AreNotEqual(a, b);
Assert.AreNotEqual(b, c);
Assert.AreNotEqual(c, a);
}
public void Restrict()
{
var obdd = new OBDD();
var a = obdd.MakeLiteral(0);
var at = obdd.Restrict(a, 0, true);
var af = obdd.Restrict(a, 0, false);
Assert.AreEqual(BDDNode.True, at);
Assert.AreEqual(BDDNode.False, af);
}
private static BDDNode AddTransition(OBDD obdd, BDDNode node, int index, int numBits, int offset)
{
for (int i = 0; i < numBits; i++)
{
int literal = i * 2 + offset;
var variable = obdd.MakeLiteral(literal);
bool hasBit = (index & (1 << i)) != 0;
if (!hasBit)
{
variable = obdd.MakeNot(variable);
}
node = obdd.MakeAnd(node, variable);
}
return(node);
}