Boolean

Set Serveroutput On

Declare
  v_Flag Boolean  := False;

  v_N1   Number(4):= &v_N1;
  v_N2   Number(4):= &v_N2;  

Begin

  v_Flag := v_N1 > v_N2;    

  If v_Flag = True
    Then Dbms_Output.Put_Line('Original v_Flag = True' );
    Else Dbms_Output.Put_Line('Original v_Flag = False');
  End If;

  If v_Flag
    Then Dbms_Output.Put_Line(v_N1|| ' > ' ||v_N2);
    Else Dbms_Output.Put_Line(v_N1|| ' < ' ||v_N2);
  End If;
End;
/