How have the courts interpreted a property settlement agreement in relation to alimony?

In Riddell v. Guggenheim, 281 F.2d 836 (9th Cir.1960), the parties negotiated a property settlement agreement that provided for monthly payments to the taxpayer's former spouse "by way of property settlement and not as alimony." Id. at 838. The payments were to terminate if the wife died or remarried. This court stated that the agreement was not clear because it unequivocally stated that the payments were for a property settlement, but nevertheless conditioned the payments. These ambiguous provisions, "especially in determining income tax liability, required the lower court to consider oral evidence of the parties' intention in drawing up the agreement (citations)." Id. at 840.