After The Harrad Experiment, another one--a marriage a quatre. Proposition is structured on the concept that all men are created not only equal but interchangeable and, for the fictional purposes of this book, unidentifiable. It's hard to keep the two male characters apart and even harder to keep them away from each other's wives when in a small California kibbutz they establish a corporate marriage (to be distinguished from spouse-swapping. Mr. Rimmer says, although the differential escaped us). All recorded as a sociological report with a little so-called academic help from Abraham Maslow, Ashley Montagu and Betty Friedan. Without going into the particulars of how Horace and Tanya Shea and David and Nancy Herndon become the Hershes all together, this is worked out and worked up on every page from the opening of the book when the two neighboring families are privy to the flushing of each other's toilets. From then on there is nothing costive about any of their responses. At the two-third mark here, Mr. Rimmer says that ""most marriages which have lasted fifteen years might be compared to a novel that two people have been reading together."" And if this were a novel instead of a protracted proposition, it might have been for better rather than for worse.