400 Series are The Patanjali Yoga Sootra series.

Explain With Vyasa Bhashya

401 - Samaadhipaada (समाधिपाद)

402 - Saadhanaapaada (साधनापाद)

403 - Vibhootipaada (विभूतिपाद)

404 - Kaivalyapaada (कैवल्यपाद)