빨간색으로 칠해놨는데 저게 무엇을 의미하는건가요 ...? AS (별칭)은 알지만 ;; WITH ? 어떤 의미이고 주로 어떨때 사용하는건가요...?

LOOP
                    IF X_CURR_DATE > L_E_DATE THEN
                       X_SQL_04 := X_SQL_04 || ', 0 ' || CHR(13) ;
                    ELSE
                       X_SQL_04 := X_SQL_04 || ', A.WORK_' || X_CURR_DATE || CHR(13) ;
                    END IF ;
                   
                    X_CURR_DATE :=  TO_CHAR(TO_DATE(X_CURR_DATE, 'YYYYMMDD') + 1, 'YYYYMMDD') ;
                    X_LOOP_CNT := X_LOOP_CNT + 1 ;

                    EXIT WHEN X_LOOP_CNT  > 31  ;
           END LOOP ;

       X_SQL := X_SQL || ' WITH A AS (    ' || CHR(13) ;
       X_SQL := X_SQL || ' SELECT A.COMP_SEQ , A.EST_SEQ ,  A.CUST_SEQ  ' || CHR(13) ;
       X_SQL := X_SQL || '          , A.FULL_FOOD_NM, A.FOOD_DES, A.FOOD_REMARK, A.FOOD_UNIT_SEQ  ' || CHR(13) ;
       X_SQL := X_SQL || '          , A.ITEM_SEQ, A.UNIT_SEQ , A.TAX_KIND, A.VAT_RATE, A.PRICE_TYPE, A.EST_TYPE , A.EST_NO , A.FINE_YN, A.SORT_ORD,  A.EST_COLOR ' || CHR(13) ;
       X_SQL := X_SQL || '          , A.PROG_STATUS AS  PROG_STATUS_TMP ' || CHR(13) ;    -- 견적 진행상태
       X_SQL := X_SQL || '          , A.MEAL_TYPE  ' || CHR(13) ;
       X_SQL := X_SQL || '          , A.EST_PERIOD_GBN  ' || CHR(13) ;     
       X_SQL := X_SQL || '          , A.UNIT_WEIGHT  ' || CHR(13) ;   -- 현품설명의 단위중량       
      
       X_SQL := X_SQL || '  , (   ' || CHR(13) ;
       X_SQL := X_SQL ||           X_SQL_01   || CHR(13) ;
       X_SQL := X_SQL || '    ) AS QTY  ' || CHR(13) ;

       X_SQL := X_SQL || '  , A.PRICE ' || CHR(13) ;

       X_SQL := X_SQL ||    X_SQL_02   || CHR(13) ;

.... (생략)