YS I 51: tasyaapi nirodhe sarvanirodhaan nirbiijaH samaadhiH.
YS III 51: tadvairaagyaad (from unattachment to the "ultimate siddhi" after mastering it) api doSa-biija-kSaye kaivalyam. Notice how similar those two suutra-s are. The main difference is that the first phrase (tasyaapi nirodhe)in I 51 has its headword in the locative singular (ekavacana saptamii vibhakti: seventh case - nirodhe) and the second phrase in the ablative singular (ekavacana pañcamii vibhakti: fifth case - sarvanirodhaat [sic!]), whereas in III 51 they are the other way round, so to speak (-vairaagyaat, -kSaye). Patañjali obviously could have used a tatpuruSa compound (tan-nirodhe) as in: abhyaasa-vairaagyaabhyaaM tan-nirodhaH (tat + nirodhaH; I 12), but for some reason he ended up using a genitive attribute construction, (tasya [...] nirodhe) or stuff. >From Taimni's comment on I 51 (huh?!): When the *capacity to perform saMyama* has been acquired...
