न धातुलोप आर्धधातुके

The गुण and वृद्धि substitutions which otherwise would have presented themselves do not take place, when such an आर्धधातुक 3.4.114 affix follows, which causes a portion of the root to be elided.
This is an exception to sūtra 3. By that sūtra iks were to be gunated or vriddhied and by sūtra 7.3.84, the root is to be gunated before all ardhadhatuka terminations. All primary affixes, that are applied directly to roots in Sanskrit, are divided into two broad classes, called sårvadhâtuka and årdhadhâtuka. The affixes marked with an indicatory श (called शित्), and the conjugational affixes, such as तिप्, तः &c., (called तिङ्) are sårvadhatuka; all other affixes are called årdhadhâtuka.

Though by the general rule, 7.3.84, the root is to be gunated before årdhadhâtuka terminations, yet it is not to be so, before those affixes which cause the लोप 'lopping off or ellipses' of a portion or a member of the original dhấtu. Thus the termination स्यामि is a first person singular termination of the future tense ( लृट् ) and is an ardhadhâtuka termination; when this is added to root जि 'to excel' the इ of जि becomes gunated and we have जेष्यामि "I shall or will excel." But in those cases where there is a lopa of the member of a root form, caused by an affix, there is no guṇation. Thus in लोलुवः "a great cutter", the original root is लू "to cut" which forms the Intensive verb लोलूय. In forming the noun of agency from the verb लोलूय, an ardhadhatuka suffix अच् 3.1.134, is added. Thus लोलूय+अच्. At this stage, by force of sūtra 2.4.74 which declares that "before the affix अच् 3.1.134 the य of the Intensive verb must be suppressed," the ya is dropped and we have लोलू+अ. Here by the general rule 7.3.84, the final ऊ would have been gunated. But by virtue of the present sūtra, no guna takes place, because here on account of the ardhadhâtuka affix अच्, a portion of the root, namely, य, has been elided; therefore no guņa takes place. Thus we have लोलुवः "a great cutter."

The word धातु "root" has been used in the sûtra, in order to indicate that the exception does not apply where there is an elision of an anubandha or of an affix. As in लूञ्+इता = लो+इता = लविता. Here the indicatory letter ञ् has been elided, but that does not prevent gunation. Similarly in रेड् the affix विच् is added to the root रिष् "to injure." Thus रिष्+विच् 3.2.75 = रिष्+व् 1.3.2 and 1.3.3 = रिष्+० 6.1.67. Here the affix व् is elided, but nevertheless, the guṇa substitute must take place in रिष्. Thus we have रिष्+० = रेष् 7.3.86 and 1.1.62 = रेड् 8.2.39.

The word ardhadhâtuka has been used to indicate that a sarvadhatuka affix which causes the elision of a portion of a root, does not prevent guna or vriddhi as in रोरवीति, (Rig Veda IV.58.3) "he roars much". रू+यङ् = रोरुव 3.1.22. रोरुय+तिप् = रोरु+ति 2.4.74. Here the sarvadhatuka affix तिप् causes the elision of य, a portion of the root. The guna substitution however takes place, and we have रोरो+ई+ति 7.3.94 = रोरवीति, the augment ईट् being added by sūtra 7.3.94.

The word "ikah" of the previous sūtra is understood in this sūtra also. The ik letters only are not gunated or vriddhied before such ardhadbatuka affixes; the other vowels may do so. Thus in अभाजि the equation is as follows:- अ+भञ्ज्+चिण् = अ+भज्+इ 6.4.33. Here the ardhadhátuka affix चिण् has caused a portion of the root भञ्ज्, to be suppressed, vis., the letter ञ् has been elided. But nevertheless the अ of भज् is vriddhied before चिण् because अ is not included in the pratyahara ik ; and the exception contained in the present sutra only applies to the ik letters. So also रञ्ज्+घञ् 3.3.18 = रज्+अ 6.4.27 = रागः 7.2.116 and 7.3.52.