BL_post_distr           Computes the Black-Litterman posterior
                        distribution.
equilibrium_mean        Solves the inverse optimization to mean-risk
                        standard optimization problem to find
                        equilibrium returns. The function is invoked by
                        BL_post_distr and arguments are supplemented by
                        BL_post_distr.
observ_normal           Example of distribution of views - normal
                        distribution
observ_powerexp         Example of distribution of views - power
                        exponential distribution
observ_ts               Example of distribution of views - Student
                        t-distribution
