Why प्रादयः (1-4-58) and उपसर्गाः क्रियायोगे (1-4-59) are द्वे सूत्रे

I do not know how and why, but just came to mind प्रोक्तमन्वभवत् (प्रोक्तम् अनु+अभवत्)

This phrase can be paraphrased in two ways 

प्रोक्तम् अनु अभवत् = It happened as was said. This is like a prediction of an astrologer coming true.

प्रोक्तम् अन्वभवत् = He experienced what was said. 

Note, the two English phrases "It happened" and "He experienced" have different subject-words 'It' and 'He'. 

In "प्रोक्तम् अनु अभवत् = It happened as was said" the word अनु is related to प्रोक्तम्. 

In प्रोक्तम् अन्वभवत् the word अनु is integral with अभवत्, i.e. the word अनु has क्रियायोग:. A word like अनु is उपसर्ग: when there is क्रियायोग:. 

That is the precise purpose why प्रादयः (1-4-58) and उपसर्गाः क्रियायोगे (1-4-59) are द्वे सूत्रे. 

When they are more related with another word as in प्रोक्तम् अनु, then they are प्रादयः. 

It is said that श्रीरामायणम् प्रोक्तम् अनु अभवत् i.e. श्रीरामायणम् happened as was scripted (by वाल्मीकि). 

Alternatively श्रीरामावतारे श्रीविष्णुभगवान् वाल्मीकिना प्रोक्तमन्वभवत् i.e. during His incarnation as श्रीराम श्रीविष्णुभगवान् experienced as was written by वाल्मीकि. 

प्रोक्तमन्वभवत् (प्रोक्तम् अनु+अभवत्) is a phrase, which illustrates how a word अनु  is a प्रादिः when related with प्रोक्तम् and is an उपसर्ग: when there is क्रियायोग: as in अन्वभवत्. 

Actually प्रादयः is a set गणः called as प्रादिगणः comprising प्र। परा। अप। सम्। अनु। अव। निस्। निर्। दुस्। दुर्। वि। आङ्। नि। अधि। अपि। अति। सु। उत् ।अभि। प्रति। परि। उप।

Note निस्। निर्। can be taken to be one and the same, rather the basic can be said to be नि:

Same logic is valid for दुस्। दुर्। The basic form can be taken to be दु:. 

I do not know why their order is as given. In alphabetical order they are अति। अधि। अनु। अप। अपि। अभि। अव। आङ्। उत् ।उप।

दु:। नि। नि:। परा। परि।प्र। प्रति।वि। सम्।सु।

Note आङ् is the grammatical name. It affixes only as आ. The grammatical name is आङ् to distinguish it from other grammatical terms such as आच् आट् आत् आप् आम्. Even a grammatical term टा a suffix, affixes as आ only. 

I wonder there are examples for all elements of प्रादिगणः that each of them is both उपसर्ग: when there is क्रियायोग: and प्रादिः when without क्रियायोग:. 

In वेदिक वाङ्मयम् even when there is क्रियायोग:, that is even when the element is उपसर्ग: they are mentioned separately. For example आ नो भद्राः क्रतवो यन्तु विश्वतः This ऋक् is interpreted with आयन्तु as the तिङन्तम्. This ऋक् can also be interpreted with only यन्तु as the तिङन्तम्. 

To examine a few 

अपि is उपसर्ग: mostly used with धातुः धा. But अपि is also अव्ययम्  

अव is उपसर्गः. But अव is also लोट् म.पु. एक. of धातुः अव् as in अव त्वं माम् in श्रीगणपत्यथर्वशीर्षम्  

परा is an adjective as in परा प्रकृतिः. In this instance it is neither प्रादिः nor उपसर्ग:. It is विशेषणम्. 

Actually it is a matter of deliberation, whether the elements are to be considered as प्रादयः or उपसर्गाः ONLY when they are with तिङन्ताः. The point is are they प्रादयः or उपसर्गाः, also when they are part of  कृदन्ताः ? Theoretically कृदन्ताः are also derived from धातवः only. But कृदन्ताः are many. The word प्रकृतिः is also कृदन्त and has प्र in it. I think the word is उपसर्ग:, only if it has क्रियायोग: in the sentence. "In the sentence" is the criterion. If in the phrase परा प्रकृतिः, if प्र in प्रकृतिः has no क्रियायोग:, then प्र is just a प्रादिः not उपसर्ग:. 

शुभमस्तु !

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