Lomashishiksha 4

Even of many u-sounds, a single articulatory effort is prescribed;
in the short, the long, and the protracted, the primary articulatory effort should not be diverse.

Even among many u-sounds, if the middle one is long,
the articulatory effort is at the beginning and the end, but the middle one is separate.

Even among many u-sounds, if the final one is long,
the articulatory effort is at the beginning and the end, while the middle one relies on a separate [effort].

Where there is a double articulatory effort at the beginning and afterwards the sound u,
that is to be known as beginning, middle, and end; 'vāyo' [and] 'uktaḥ' is the example.

Where there is a single articulatory effort at the beginning and afterwards the sound u,
that is to be known as beginning and end; 'vāyo śukraḥ' is the example.

If the preceding sound is non-conjunct and the following sound is subsequent,
and it is conjoined with an u-sound, there should be a repetition of articulatory effort.

The consonants following a vowel, and those suitable at the end of an u-sound—
one should know the articulatory effort here of these, and then of o and ḍ.

Wherever two contiguous labial vowels are joined in conjunction,
there should be a single articulatory effort; otherwise the articulatory effort is doubled.

If two sounds are labials, even when followed by a non-conjunct,
one should produce double labiality with them; 'ojiṣṭhaṃ pupu-' is the example.

Thus ends the fourth section.