H and W were married on August 7, 1948, and separated approximately 21 years later on August 7, 1969. On October 6, 1970, H filed a petition for dissolution of marriage on the ground of irreconcilable differences which have caused the irremediable breakdown of the marriage. W filed her response seeking legal separation on the same ground, irreconcilable differences which have caused the irremediable breakdown of the marriage. W moved the court to dismiss H's petition on grounds that certain provisions of the Family Law Act enacted in 1969 (Stats. 1969, ch. 1608), particularly Civil Code, sections 4506, subdivision (1) and 4507, are violative of the California and federal Constitutions on several bases. The motion was denied, the matter proceeded to trial, and the court rendered an interlocutory judgment of dissolution of the marriage placing custody of the minor children of the parties with W, providing for spousal and child support and dividing the marital property. W appealed. W contends: Granting H's petition for dissolution of marriage on the ground of irreconcilable differences as specified in Civil Code, section 4506, subdivision (1) is violative of article I, section 10 of the United States Constitution and article I, section 16 of the California Constitution prohibiting the enactment of any law impairing the obligations of contract; Granting H's petition for dissolution of the marriage on the ground of irreconcilable differences as specified in Civil Code, section 4506, subdivision (1) constitutes a retroactive application of law to Wife depriving her of a vested interest in her married status in violation of the due process of law guarantees contained in article I, section 13 of the California Constitution and the Fourteenth Amendment to the United States Constitution; Granting H's petition for dissolution of the marriage on the ground of irreconcilable differences is violative of the constitutional guarantees of due process of law in that Civil Code, sections 4506, subdivision (1) and 4507 are too vague and ambiguous to assure uniform application.