Method of Argument

I refer to the lecture note on The Later Developments in Mahayana Buddhist Philosophy, Page 2 to 4.

To defend the rightness of the Madhyamaka philosophy, the Prasangika School used Prasanga Vakya Anumanna (or the reductio ad absurdum) method while the Svatantrika School used Svatantra Anumana (or the independent syllogism three elements) method.

We knew the the Chinese monk named Xuanzang (602 to 664CE) who went to India to study got involved in a 5-day long religious debate.

Does anyone know what method of argument he used?

Thanks and regards,
tan boon ann