Program code anaylsis

$1$ DECLARE

$2$ a NUMBER:$=0$;

$3$ b NUMBER;

$4$ upper$-$limit NUMBER :$=4$;

$5$ BEGIN

$6$ dbms$\_$output.put$\_$line$($Program started.$\text{'})$;

$7$outerloop$$

$8$ LOOP

$9$ a:$=$a$+1$;

$10$ b:$=$l;

$11$inner loop$$

$12$ LOOP

$13$ EXIT outer$\_$loop WHEN a $>$ upper$\_$limit;

$14$ dbms$\_$output.put$\_$line$($a$)$;

$15$ b:$=$b$+$l;

$16$ EXIT inner$\_$loop WHEN b$>$a;

$17$ END LOOP;

$18$ END LOOP;

$19$ dbms$\_$output.put$\_$line$(\text{'}$Program completed.$\text{'})$;

$20$ END;

$/$

Please fill below program $/$code explanation for missing lines

Code Explanation: $($some lines are given to you$)$

$$ Code line $2-3$: Declaring the variable $$a$$ and $$b$$ as $$NUMBER$$ data type.

$$ Code line $4$: Declaring the variable $$upper$\_$limit$$ as $$NUMBER$$ data type with value $4$

$$ Code line $6$:

$$ Code line $7$:

$$ Code line $9$:

$$ Code line $11$:

$$ Code line $13$: EXIT what?

$$ Code line $14$:

$$ Code line $15$: Increments by $.......$

$$ Code line $16$: