ListTerm deleteFromList(int index, ListTerm l) {
ListTerm r = new ListTermImpl();
ListTerm last = r;
int i = 0;
for (Term t : l) {
if ((i++) != index) last = last.append(t.clone());
}
return r;
}
ListTerm deleteFromList(Term element, ListTerm l, Unifier un) {
Unifier bak = un;
ListTerm r = new ListTermImpl();
ListTerm last = r;
for (Term t : l) {
boolean u = un.unifies(element, t);
if (u) un = bak.clone();
else last = last.append(t.clone());
}
return r;
}