AGRICULTURE - COMMON ORGANIZATION OF MARKETS - BEEF - FROZEN MEAT INTENDED FOR PROCESSING - SUSPENSION OF THE LEVY ON IMPORTATION - PROOF OF PROCESSING - DETAILED RULES - REGULATION NO 3584/81 - TEMPORAL APPLICATION ( COMMISSION REGULATION NO 1136/79 , ART . 2 ( 3 ) AND ( 4 ), AS AMENDED BY REGULATION NO 3584/81 )