BE CONSIDERED SEISED OF A CASE FOR THE PURPOSES OF ARTICLE 21 OF THE CONVENTION MUST BE APPRAISED AND RESOLVED, IN THE CASE OF EACH COURT, ACCORDING TO THE RULES OF ITS OWN NATIONAL LAW . THAT REASONING WAS BASED ON THE ABSENCE OF ANY INDICATION IN THAT ARTICLE OF THE NATURE OF THE RELEVANT PROCEDURAL FORMALITIES, SINCE THE CONVENTION DOES NOT HAVE THE AIM OF UNIFYING THOSE FORMALITIES, WHICH ARE CLOSELY CONNECTED WITH THE PROCEDURAL SYSTEMS OF THE DIFFERENT MEMBER STATES . ACCORDINGLY, IT CANNOT PREJUDGE THE INTERPRETATION OF THE SUBSTANTIVE SCOPE OF THE CONDITIONS OF LIS PENDENS LAID DOWN IN ARTICLE 21 .
13 IT IS THEREFORE IN THE LIGHT OF THE AFORESAID OBJECTIVES AND WITH A VIEW TO ENSURING CONSISTENCY AS BETWEEN ARTICLES 21 AND 27 ( 3 ) THAT THE QUESTION WHETHER A PROCEDURAL SITUATION OF THE KIND AT ISSUE IN THIS CASE IS COVERED BY ARTICLE 21 MUST BE DEALT WITH . THE SALIENT FEATURES OF THAT SITUATION ARE THAT ONE OF THE PARTIES HAS BROUGHT AN ACTION BEFORE A COURT OF FIRST INSTANCE FOR THE ENFORCEMENT OF AN OBLIGATION STIPULATED IN AN INTERNATIONAL CONTRACT OF SALE; AN ACTION IS SUBSEQUENTLY BROUGHT AGAINST HIM BY THE OTHER PARTY IN ANOTHER CONTRACTING STATE FOR THE RESCISSION OR DISCHARGE OF THE SAME CONTRACT .
14 IT MUST BE OBSERVED FIRST OF ALL THAT ACCORDING TO ITS WORDING ARTICLE 21 APPLIES WHERE TWO ACTIONS ARE BETWEEN THE SAME PARTIES AND INVOLVE THE SAME CAUSE OF ACTION AND THE SAME SUBJECT-MATTER; IT DOES NOT LAY DOWN ANY FURTHER CONDITIONS . EVEN THOUGH THE GERMAN VERSION OF ARTICLE 21 DOES NOT EXPRESSLY DISTINGUISH BETWEEN THE TERMS "SUBJECT-MATTER" AND "CAUSE OF ACTION", IT MUST BE CONSTRUED IN THE SAME MANNER AS THE OTHER LANGUAGE VERSIONS, ALL OF WHICH MAKE THAT DISTINCTION .
15 IN THE PROCEDURAL SITUATION WHICH HAS GIVEN RISE TO THE QUESTION SUBMITTED FOR A PRELIMINARY RULING THE SAME PARTIES ARE ENGAGED IN TWO LEGAL PROCEEDINGS IN DIFFERENT CONTRACTING STATES WHICH ARE BASED ON THE SAME "CAUSE OF ACTION", THAT IS TO SAY THE SAME CONTRACTUAL RELATIONSHIP . THE PROBLEM WHICH ARISES, THEREFORE, IS WHETHER THOSE TWO ACTIONS HAVE THE SAME "SUBJECT-MATTER" WHEN THE FIRST SEEKS TO ENFORCE THE CONTRACT AND THE SECOND SEEKS ITS RESCISSION OR DISCHARGE .
16 IN PARTICULAR, IN A CASE SUCH AS THIS, INVOLVING THE INTERNATIONAL SALE OF TANGIBLE MOVEABLE PROPERTY, IT IS APPARENT THAT THE ACTION TO ENFORCE THE CONTRACT IS AIMED AT GIVING EFFECT TO IT, AND THAT THE ACTION FOR ITS RESCISSION OR DISCHARGE IS AIMED PRECISELY AT DEPRIVING IT OF ANY EFFECT . THE QUESTION WHETHER THE CONTRACT IS BINDING THEREFORE LIES AT THE HEART OF THE TWO ACTIONS . IF IT IS THE ACTION FOR RESCISSION OR DISCHARGE OF THE CONTRACT THAT IS BROUGHT SUBSEQUENTLY, IT MAY EVEN BE REGARDED AS SIMPLY A DEFENCE AGAINST THE FIRST ACTION, BROUGHT IN THE FORM OF INDEPENDENT PROCEEDINGS BEFORE A COURT IN ANOTHER CONTRACTING STATE .
17 IN THOSE PROCEDURAL CIRCUMSTANCES IT