for循环

FOR i in 3..8
      LOOP
          IF ( V_SLOTNUM(i) IS NULL) THEN
              TAG := i-2;
              SIGN_EXIT := TRUE;
              SIGN_FOUND := TRUE;
              EXIT WHEN SIGN_EXIT;
          ELSE
              FOR j in 1..8
                LOOP
                    IF ( V_SLOTNUM(i) = V_SLOTNUM2(j) AND V_RACKNUM(i) = V_RACKNUM2(j) ) THEN
                      SIGN_EXIT := TRUE;
                      SIGN_EXIST_IN_MODULE := TRUE;
                      EXIT WHEN SIGN_EXIT;
                    END IF;
                END LOOP;
              IF ( SIGN_EXIST_IN_MODULE = FALSE ) THEN
                 TAG := i-2;
                 SIGN_FOUND := TRUE;
                 EXIT WHEN SIGN_EXIT;
              END IF;
          END IF;
       END LOOP;