The affixes ini and ṭhan come in the sense of matup after the prātipadika (Nominal Stems) ending in short a and in the alternative matup also comes.,
Thus दण्डिन्, दण्डिकः, छत्रिन् nom. छत्री, छत्रिकः ॥ The word अन्यतरस्याम् 5.2.96 is understood here also, so we have मतुप्, as दण्डवान्, छत्रवान् ॥ Why do we say 'short अ'? Observe खट्वावान्. Here there is neither इन् nor ठन् ॥
These two affixes इनि and ठन् do not come after words of one syllable, after words ending in krit-affixes, after words denoting genus (jati), and when the construction is that of locative. As स्व and ख form only स्वावान्, खवान् ॥ Krit: as, कारकवान् ॥ Genus, as, व्याघ्रवान्, सिंहवान् ॥ Locative; as दण्डा अस्यां सन्ति = दण्डवती शाला ॥ There are, however, some exceptions to this, as krit :-- कार्यिन्, कार्यिकः हार्यिन्, हार्यिकः ॥ Genus (jati) :-- तण्डुलिन्, तण्डुलिकः ॥,