\NewDocumentCommand  \op        {m} {\operatorname{#1}}
\DeclareMathOperator \img           {img}

% Geometry
\DeclareMathOperator \dist          {d}
\DeclareMathOperator \point         {\text{т.}}
\NewDocumentCommand  \vect      {m} {\overrightarrow{#1}}
\NewDocumentCommand  \ray       {m} { #1 \mkern3mu \vect{\vphantom{x}} }

% Linear algebra
\DeclareMathOperator \rank          {rank}
\DeclareMathOperator \linspan       {span}

% Probability
\NewDocumentCommand  \distr     {m} {\operatorname{\mathbf{#1}}}
\DeclareMathOperator \Prob          {P}
\DeclareMathOperator \Expect        {E}
\DeclareMathOperator \var           {var}
\DeclareMathOperator \cov           {cov}
\DeclareMathOperator \PGF           {PGF}
\DeclareMathOperator \MGF           {MGF}
\DeclareMathOperator \corr          {\rho}
