CREATE OR REPLACE PROCEDURE top_protected_proc  
  ACCESSIBLE BY (PROCEDURE top_trusted_proc)  
AS  
BEGIN  
  DBMS_OUTPUT.put_line('Executed top_protected_proc.');  
END;

CREATE OR REPLACE PROCEDURE top_trusted_proc AS  
BEGIN  
  DBMS_OUTPUT.put_line('top_trusted_proc calls top_protected_proc');  
  top_protected_proc;  
END;

EXEC top_protected_proc

EXEC top_trusted_proc