Code of Organization and Civil Procedure (Cap. 12), article 240

240. (1) Any party may avail himself of an appeal entered from a judgment, including a partial judgment and from a head or heads of any judgment, or from an interlocutory decree and may enter a cross appeal not only in respect of the judgment, partial judgment, head or heads of a judgment, or interlocutory decree appealed from, but also in respect of any judgment or heads thereof or interlocutory decrees given in the same cause even if not appealed from by the appellant. Such cross appeal may be made even against or by any party not being one against whom an appeal is directed in terms of article 144(1): Provided that a party may not so avail himself of the appeal in respect of the particular judgment, if he has already appealed from such judgment or any head thereof. (2) The party who intends to avail himself of such appeal shall make a declaration to that effect in the answer stating therein his demands and the grounds for his cross appeal. Cross-appeal to hold good notwithstanding abandonment of appeal.