Can't find 'viyoga' in the YS. OTOH, there is the word viniyoga in III 6: tasya bhuumiSu viniyogaH.
Taimni's translation: Its (of saMyama) use by stages. viniyoga m. apportionment , distribution , division Nir. ; appointment to (loc.) , commission , charge , duty , task , occupation MBh. R. &c. [970,3] ; employment , use , application (esp. of a verse in ritual) TA1r. Hariv. &c. ;
