Karnatakabhashabhushana 6.12.2

6.12.2

viśēṣyōttarapadasya viśēṣaṇarōpatayāvasthitasya pūrvapadasya upāntyasvarādēr avayavasya lōpō bhavati.

Of a prior member standing in the form of a qualifier whose posterior member is a substantive, there is elision of the part beginning with the penultimate vowel.