private bool Add(SymbolicConstant <T> lower, SymbolicConstant <T> upper)
{
if (LessThan(upper, lower) == true)
{
// Cycle!
return(false);
}
if (lower.Equals(upper))
{
return(true);
}
if (!_Orders.TryGetValue(lower, out var lowerNode))
{
lowerNode = new OrderNode(lower);
_Orders.Add(lower, lowerNode);
}
if (!_Orders.TryGetValue(upper, out var upperNode))
{
upperNode = new OrderNode(upper);
_Orders.Add(upper, upperNode);
}
upperNode.Previous.Add(lowerNode);
lowerNode.Next.Add(upperNode);
return(true);
}
public bool?LessThan(SymbolicConstant <T> a, SymbolicConstant <T> b)
{
if (!a.Symbolic && !b.Symbolic)
{
return(a.Constant.CompareTo(b.Constant) < 0);
}
if (a.Equals(_Min) || b.Equals(_Max))
{
return(true);
}
if (a.Equals(_Max) || b.Equals(_Min))
{
return(false);
}
// Need to find a path from a to b
if (!_Orders.TryGetValue(a, out var nodeA))
{
// ?!? Unable to compare
return(null);
}
var result = nodeA.HasNext(b);
if (result)
{
return(true);
}
result = nodeA.HasPrevious(b);
if (result)
{
return(false);
}
return(null);
}
public bool?LessOrEqual(SymbolicConstant <T> a, SymbolicConstant <T> b) => a.Equals(b) ? true : LessThan(a, b);