A of land for the construction of a residential house in any of the territory of Delhi, in his own name or in the name of his spouse or any of his dependent children, on leasehold or free-hold basis. It is incorrect to say that Rule 25 was not applicable to his case as the said rule was not B retrospective and the alleged disqualification of purchasing the said property had incurred prior to the adoption of the Rules. Merely because a person who had become a member of the society at a point of time when the disqualification mentioned in Rule 25 was not in c existence and because of the said rule would cease to be a member of the society does not necessarily mean that the said rule is retrospective. The most concrete cases wherein laws are made retrospective are those in which the date of commencement is earlier than 0enactment, or which validate some invalid law, otherwise, every statute affects rights which would have been in existence but for the statute and a statute does not become a retrospective one because a part of the requisition for its action is drawn from a time antecedent E to its passing. In this view of the matter, Rule 25(2) is not retrospective. All that Rule 25(2) does is that it operates in future, though the basis for taking action is the factum of acquiring a plot in the past. Thus when by virtue of Rule 25(2), a member is deemed to have ceased to be a member of the society, the cessation operates from April F 2, 1973, when the rules came into force. [Paras 8, 12, 15) (981-A-F; 984-A-H; 985-A; 986-D~F]