\newcommand{\bx}{\mathbf{x}}
\newcommand{\bz}{\mathbf{z}}
\newcommand{\by}{\mathbf{y}}
\newcommand{\bff}{\mathbf{f}}
\newcommand{\btheta}{\boldsymbol{\theta}}
\newcommand{\bfeta}{\boldsymbol{\eta}}
\newcommand{\bvartheta}{\boldsymbol{\vartheta}}
\newcommand{\bg}{\mathbf{g}}
\newcommand{\tr}{\tilde{r}}
\newcommand{\tp}{\tilde{p}}
\newcommand{\pois}{\text{Pois}}