(a) The integral of the joint pdf of the likelihood ratios under class B, along lines with slope m*. The resulting integral is a 1-D function, and is denoted as fB,m* (v). (b) The integral of the joint pdf of the likelihood ratios under class N, along lines with slope m*. The resulting integral is a 1-D function, and is denoted as fN,m* (v). Note that fB,m* (v) and fN,m* (v) are not Gaussian; in particular, they are zero for v ≤ 0 and u ≤ 0, respectively.