public virtual int lastIndexOf(ATerm el, int start)
{
int result;
if (start < 0)
{
start += length + 1;
}
if (start > length)
{
throw new ArgumentException("start (" + start + ") > length of list (" + length + ")");
}
if (start > 0)
{
result = next.lastIndexOf(el, start - 1);
if (result >= 0)
{
return(result + 1);
}
}
if (first == el)
{
return(0);
}
else
{
return(-1);
}
}