The 18th century Sde-dge redaction of the Sde-srid Saṅs-rgyas-rgya-mtshoʾs Vai dūrya gʹyaʾ sel, with the Sñan sgron ñis brgya brgyad pa : two monumental works clarifying and elucidating controversial points in the author's renowned astronomical and astrological treatise the Vai dūrya dkar po