y one of
    the y_j, for j = 1 to 12, is false.  Therefore, an expression like

    (( x_1 ),( x_2 ), ..., ( x_11 ),( x_12 ))

    avers that exactly one of the x_i is true.  This is the expression
    of a partition on the universe of discourse, in this case dividing
    it up into exactly 12 exhaustive and mutually exclusive categories.

JA: Observe that the number of variable tokens that are needed in this
    form of expression is a linear function, often described as &quot;O(x)&quot;,
    in the numbe