This is `log-sum-inv`

. In essence, the same as Log( {convex} ) . Make modifications, such as having `log(B)`

rather than 0 as 1st element in vector argument of log_sum_exp,. no H^2 term, and A_i in place of GAMMA.

Note: edited to correct `log(B)`

to `log(1/B)`

.

Note: reverted to original., i.e., log(B), not log(1/B)