Differences in attainments among Arahants

In the Anguttara Nikaya it is said that by possessing seven qualities one can attain direct knowledge of the Four Analytical Knowledges: >41. Mastery. > >"Bhikkhus, possessing seven qualities, Sāriputta exercises mastery over his mind and is not a servant of his mind. What seven? Here, (1) Sāriputta is skilled in concentration, (2) skilled in the attainment of concentration, (3) skilled in the duration of concentration, (4) skilled in emergence from concentration, (5) skilled in fitness for concentration, (6) skilled in the area of concentration, and (7) skilled in resolution regarding concentra- tion. Possessing these seven qualities, Sāriputta exercises mas- tery over his mind and is not a servant of his mind". > > "Bhikkhus, when he possessed seven qualities, Sāriputta realized for himself with direct knowledge the four analytical knowledges". > >-- T*he Numerical Discourses of the Buddha - A Translation of the Anguttara Nikaya by Ven. Bhikkhu Bodhi: The Book of the Sevens, Sutta 39, p. 1023* What are the Four Analytical Knowledges?