Why sql plan is differet from trace and elect plan_table_output from TABLE (DBMS_XPLAN.DISPLAY_CURSO

I had one sql

SELECT pp.prt_process_no

from

  prt_process pp,prw_contr_state pcs,prw_valid_trans pvt where

  pp.prt_process_no > :p1 AND prt_sys_status (pp.prt_status_code) NOT IN

  (:"SYS_B_0",:"SYS_B_1") AND pvt.prw_transition_id = :p2 AND

  pcs.prw_control_id = pvt.prw_control_id AND pp.prt_type_code =

  pcs.prt_type_code AND pp.prt_class_code = pcs.prt_class_code AND

  (pp.prt_subclass_code = pcs.prt_subclass_code) AND (pp.prt_status_code =

  pcs.prt_status_code OR pcs.prt_status_code IS NULL) AND