Tibetan Buddhist sources are full of surprises and this is one of the many reasons why I love studying Tibetan Buddhism. And I like mKhan-chen Ngag-dbang-chos-grags, or rather his gZhung chen drug gi ’bel gtam. This title seems to be a popular title. The actual title is long and reads differently. The work is simply rich. It is not that I agree with everything stated in it. It has even subtle humor. This brings me the distinction between the “Bu-Do Duo” (Bu-Do-gnyis), that is, Bu-ston and Dol-po-pa. It states that the difference between their philosophical positions can be reduced to a mere single letter r (’Bel gtam, p. 568): (a) Bu-ston’s proposition: chos dbyings bden pa yin kyang bden par med |. (b) Dol-po-pa’s objection: chos dbyings chos can | bden par yod par thal | bden pa yin pa’i phyir |. Dol-po-pa’s implication: chos dbyings bden pa yin| chos dbyings bden par yod |. In other words: (a) Bu-ston: chos dbyings bden par med. (b) Dol-po-pa: chos dbyings bden par yod. The joke is supposed to be: (a) Bu-ston: r med. (b) Dol-po-pa: r yod.