(1) j= 1, j < = 2 holds, so the output i+j=4.

(2) after j increases (j++), j = 2 and j < =2 holds, so i+j=5 is output.

(3) after increasing j, j = 3, j.

2. after I reduction, I = 2, I >；; = 1 hold.

( 1)j= 1，i+j=3

(2)j = 2； i+j=4

(3)j=3 is not valid.

3. after I reduction, I = 1, I >；; = 1 hold.

( 1) j= 1，I+j = 2；

(2)j = 2； I+j = 3；

(3)j=3 is not valid.

4. after I reduction, I = 0, I >；; = 1 is invalid, and the loop ends.