public Equivalence(EnsembleAbstrait e) {
        if(e == null) throw new IllegalArgumentException();

        this.tabRep = new Elt[Elt.MAXELT.val()+1];
        this.numVersion = 0;
        this.sousJac = e.clone();
        for (int i = 1; i <Elt.MAXELT.val()+1 ; i++) {
            Elt temp = new Elt(i);
            if(e.contient(temp)){
                tabRep[i] = temp;
            }else{
                tabRep[i] = null;
            }
        }
    }