This takes us to a very confusing problem in the study of the Mandukya Upanishad.
There are some like Professor Deussen, who claim and profess to prove that even the twelve prose passages belong to Sri Gaudapada; that is to say according to the Professor ( in his work The philosophy of the Upanishad-s), there is no Mandukya as such but the entire literature is only a Parakarna Granth, a treatise on Vedanta categories.
In order to prove his theory, he quotes Swami Adi Sankaracharya and says that in the eyes of Swamiji this is no Upanishad at all but it is only 'a book of categories' ( Prakarna Granth ) because in none of his genuine works has Swamiji quoted Mandukya.
Thus it is far cry from Sri Madhavacharya to Professor Deussen; Madhavacharya claiming that even the karika belongs to the Upanishad, which Deussen insists that even the Mantra-s are nothing but the karika.
To be continued ....