using the unary predicates H for "human", U for "unhapppy" and the binary predicate M$($x$,$ y$)$ saying that x is married with y and y is married with x $($thus$,$ the fact that A is married with B can be expressed either with MA$,$ B$)$ or M $($B$,$ A$)).$

$1.$ every unmarried human is unhappy

$2.$ it is not possible to be married with two different humans