यथासंख्यमनुदेशः समानाम्
When a certain relation is given between two groups having same number of elements, then the relation is considered to exist only between the correspondingly positioned members of the two groups.
Word by word (padaccheda)
- Indeclinable An avyaya such as च "and", वा "optionally", न "not".
- Term / subject Prathamā (1st case): the term being defined, or the subject of the statement.
- Of Ṣaṣṭhī (6th case): "of X". In this kind of sūtra it marks a relation, not a substitution.
A table read this way: 4.1.2 सुप् The 21 case endings →A table read this way: 3.4.78 तिङ् The 18 verb endings →A table read this way: 3.4.82 लिट् Perfect (liṭ) parasmaipada endings →A table read this way: 3.4.101 ङिल्लकार Endings of the ṅit lakāras (laṅ, liṅ, luṅ, lṛṅ) →A table read this way: 6.1.77 इको यणचि Vowels to semivowels →A table read this way: 6.1.78 एचोऽयवायावः Diphthongs before a vowel →A table read this way: 7.1.1 युवोरनाकौ यु and वु in affixes →A table read this way: 7.1.2 प्रत्ययादि Initial sounds of affixes →A table read this way: 7.1.12 टाङसिङसाम् Endings after a-stems →
Commentary
When a rule involves the case of equal numbers of substitutes and of things for which these are to be substituted, their mutual correspondence or assignment of each to each, is according to the order of enumeration.
Thus sutra (III.I 134) (नन्दिग्रहिपचादिभ्यो ल्युणिन्यचः) declares- 'the affixes ल्यु, णिनि and अच् are applied to नन्दि, ग्रहि and पच् class of words.' It means the affix ल्यु is applied to the words of नन्दि class, the affix णिनि to words of ग्रहि class, and अच् to words of पच् class. The application must be respectively according to order, and not hap-hazard. Similarly in 6.1.77 इको यणचि (if a vowel follows) in the place of इ, उ, ऋ, लृ there is यण् i. e., य्, र्, ल्, व् ॥ So also see Sutra. 4.3.94 (तूदीशलातुरवर्मतीकूचवाराड् ढक् छण् ढञ् यकः) where the four affixes dhak, chhan dhan, and yak are applied respectively to the words tudi, salatura, varmati and kuchavara; i.e., the first affix in the order of enumeration to the first word, the second affix to the second word, &c. As तौदेयः, शालातुरीयः, वार्मतेयः and कौचवार्य्यः ॥
Why do we say 'of equal members'? This rule will not apply if the number of substitutes and of things for which these are to be substituted are unequal. As in sutra (1.4. 90), लक्षणेत्थभूताख्यानभागवीप्सासु प्रति पर्यनवः for here the words lakshana, &c., in the first part of the sutra are four in number, while the words prati &c. are only three. That sutra therefore must be read as thus. "The words प्रति, परि and अनु are karma pravachaniya, whenever they indicate either lakshana (a mark), itthambhuta khyana (a statement of mere circumstance); bhaga (division); or vipsa (desire)."
Śrīśa Chandra Vasu, The Ashtadhyayi of Panini (1897), via ashtadhyayi.com.