(a) the surviving spouse of the hereditary disabled person may require the holder of the estate whose surviving spouse had, at the time of the transfer, the expectation referred to in Article 101, to recover half of the heir`s property if the transferee retains the property or, if not, half of its proceeds or, if not, half of its value at the time of the transfer; (a) half of the Community patrimony and half of the quasi-Community patrimony shall be managed, distributed or otherwise treated as if a spouse had survived and that half belonged to that spouse. Sometimes the problem of the transfer of a given common property can be solved by the fact that the spouses accept the use of the aggregate theory of common property. The aggregate theory of common ownership is essentially the idea that each spouse owns 1/2 of the common property by value and not by object. Therefore, according to the theory of aggregate, a spouse can bequeath 1/2 of his assets without mentioning a particular asset. According to item theory, a spouse only has the power to dispose of his or her 1/2 share of a given community patrimony. The standard California rule is to follow the theory of the article, unless the spouses agree otherwise in writing. With respect to the transfer of collective ownership and quasi-collective ownership to a revocable trust, Articles 100 and 101 require that those assets retain their character as a whole for the purposes of a division provided by the trust. This Section shall apply to all transfers before, on or after 1 January 2000. In my example, if there is no “aggregate theory” agreement, the transfer of 100% of the house to Trust A and 100% of the shares to Trust B is an exchange, half of the house for half of the shares. In the event that the house and shares have increased in value at the time of the “exchange”, a taxable transaction has taken place and each trust is presumed to have made a sale of assets subject to taxation, to the extent of the profit incurred. (b) Notwithstanding subdivision (a) the spouses may agree in writing to allocate their Community property on the basis of a non-proportional distribution of the total value of the Community patrimony or on the basis of an allocation of each property or asset of the common property or in part on each basis. Nothing in this subdivision should be interpreted in such a way that this written agreement is necessary to permit or recognize a non-proportional distribution of common property. .