finding the language of a PDA
(q0, a, z) (q0, az)
(q0, a, a) (q0, aa)
(q0, b, a) (q1, a) [ Indicates no operation only state change ]
(q1, b, a) (q2, a) [ Indicates no operation only state change ]
(q2, b, a) (q3, ) [Indicates pop operation ]
(q3, b, a) (q2, a ) [ Indicates no operation only state change ]
(q3, , z) (qf, z )