The language of this particular oral agreement simply does not permit such construction. Under the principle announced in McWilliams v. McWilliams, 110 Colo. 173, 132 P.2d 966, and Campbell v. Goodbar, 110 Colo. 403, 134 P.2d 1060, if the property rights and obligations of the parties to a divorce action who have entered into a settlement agreement are to rest upon the court decree, then any such agreement as to those rights should be fully and specifically set forth in the decree in order that the duties and rights can be definitely ascertained from the decree itself. In the instant case neither the interlocutory nor the final decree contain any language which under any stretch of the imagination would indicate that it was their mutual intent to cancel these arrearages.

The question posed here is: May the plaintiff assail the settlement agreement in a separate action as fraudulent, or, under the circumstances shown, was the agreement merged in the divorce decree so as the render a separate action thereon a collateral attack on such decree? We think that McWilliams v. McWilliams, 110 Colo. 173, 132 P.2d 966; Campbell v. Goodbar, 110 Colo. 403, 134 P.2d 1060; Edwards v. Edwards, 113 Colo. 390, 157 P.2d 616, and the later case of the United States National Bank v. Bartges, 120 Colo. 317, 210 P.2d 600, have resolved the question contrary to the contentions of the defendant. The rule announced in those cases may be summarized as follows: Where the trial court in a divorce action has had no part in determining the property and financial rights of the parties, other than to approve and confirm an agreement purporting to settle all such financial and property rights, the incorporation of such agreement by reference in the interlocutory or final decree in the action does not make the terms of such agreement an order or decree of the court; is not a determination by the court of the respective rights of the parties, but is their voluntary adjustment of their differences, and unless the terms thereof are adopted by the court and fully and specifically set forth in the order or decree, the rights of the parties rest wholly upon the contract and not

The court, in sustaining the position of the wife, held that the approval of the agreement by the court, the terms of which were not set forth in the decree itself, operated to make the rights of the parties rest upon the contract as contractual and not upon the decree as decreed rights and obligations; moreover, the court specifically pointed out that if the purported rights and obligations of the parties to a divorce action, where they have previously entered into a property agreement, are to rest upon the decree, then such agreement in respect to those rights and obligations should be fully and specifically set forth in the decree so that such duties, obligations and rights may be ascertained from the decree itself. Later, in the case of Campbell v. Goodbar, 110 Colo. 403, 134 P.2d 1060, the Colorado court reiterated and applied the rule announced in McWilliams v. McWilliams, supra. In this case the settlement agreement was filed with the clerk of the court.

The McWilliams case is directly in point on the pending issue. In Campbell v. Goodbar, 110 Colo. 403, 134 P.2d 1060, there was a property settlement agreement containing provision for monthly alimony payments which was filed with the clerk of the divorce court before the decree was entered. The decree provided:

This unquestionably is the law in Colorado. Kastner v. Kastner, 90 Colo. 280, 9 P.2d 290; McWilliams v. McWilliams, 110 Colo. 173, 132 P.2d 966; Campbell v. Goodbar, 110 Colo. 403, 134 P.2d 1060; Edwards v. Edwards, 113 Colo. 390, 157 P.2d 616. Counsel for defendants state in their brief that they have found no Kansas case in which the question of the necessity for incorporation at length of a property division agreement in the divorce decree has been decided. They contend that the inference of some cases is that such incorporation is not necessary.

However, on December 7, 1942, we held the contrary, and a few weeks later reaffirmed that holding. McWilliams v. McWilliams, 110 Colo. 173, 132 P.2d 966; Campbell v. Goodbar, 110 Colo. 403, 134 P.2d 1060. About six weeks after the announcement in the McWilliams case defendant reduced his payments, as above recited, and he herein seeks, by reason of this alleged mistake of law and fact (which if any mistake at all was clearly one of law), to put himself in the position he would have occupied had that conception of the law which he says was held by the parties and their attorneys at the time of the execution of "A" been correct.