private int CompareArgs(IList <IFOLNode> args1, IList <IFOLNode> args2)
{
// Compare argument sizes first
var rVal = args1.Count - args2.Count;
if (rVal == 0 && args1.Count > 0)
{
// Move forward and compare the
// first arguments
ITerm t1 = (ITerm)args1[0];
ITerm t2 = (ITerm)args2[0];
if (t1.GetType() == t2.GetType())
{
// Note: Variables are considered to have
// the same order
if (t1 is Constant)
{
rVal = t1.GetSymbolicName().CompareTo(t2.GetSymbolicName());
}
else if (t1 is Function)
{
rVal = t1.GetSymbolicName().CompareTo(t2.GetSymbolicName());
if (0 == rVal)
{
// Same function names, therefore
// compare the function arguments
rVal = this.CompareArgs(t1.GetArgs(), t2.GetArgs());
}
}
// If the first args are the same
// then compare the ordering of the
// remaining arguments
if (0 == rVal)
{
rVal = this.CompareArgs(args1.Skip(1).ToList(), args2.Skip(1).ToList());
}
}
else
{
// Order for different Terms is:
// Constant > Function > Variable
if (t1 is Constant)
{
rVal = 1;
}
else if (t2 is Constant)
{
rVal = -1;
}
else if (t1 is Function)
{
rVal = 1;
}
else
{
rVal = -1;
}
}
}
return(rVal);
}