The contract of incorporation or the articles of association, as the case may be, must, on pain of nullity, and subject to the joint and several liability of the signatories, contain an express statement, either that no funds are encumbered by the lien or pledge provided for in Chapters I to III of Title IV of this Book, or, if this is not the case, that no opposition has been lodged prior to the accession of one of the members or that its release has been ordered by the courts.