deriv LSK ETT STT aSTA ALPH OLDHOMEPAGE NEWHOMEPAGE
Several words are /samAnAdhikaraNa (coreferential) when they have the same referent.
Example. In the sentence —
alpaz zakuniH अल्पः शकुनिः "the bird is small"
the word zakuniH शकुनिः describes a bird and the word kRSNaH कृष्णः describes that same bird, so the two words are /samAnAdhikaraNa.
Now, in the sentence —
alpaz zakuniH patati अल्पः शकुनिः पतति "a small bird is flying"
the two first words are still coreferential, and the referent of the verb **patati पतति is that same bird (because it is a verb that shows the object). Therefore all three words are /samAnAdhikaraNa.
When several words are coreferential in the same Sanskrit sentence, there is always a noun that is the boss, and the other words linkto it. EG, in the last example, zakuniH शकुनिः is boss, alpaH अल्पः links to zakuniH शकुनिः, and patati पतति too linksto zakuniH शकुनिः. This makes alpaH अल्पः get its gender and /sup from zakuniH शकुनिः, and makes patati पतति get its number and person from zakuniH शकुनिः.
/pANini does not bother to mention this fact; he just takes it for granted — too obvious to be mentioned.
May I say that the words in /samAnAdhikaraNa are in "apposition"?
Fine with me. But be careful. In English grammar jargon, only expressions like "Sindbad the sailor" and "his wife Sonia" are said to be appositions. While the Sanskrit /samAnAdhikaraNa is much wider — the two words kRSNaz zakuniH कृष्णः शकुनिः "a black bird" are two nouns in /samAnAdhikaraNa.