mysymbols.sty

\newcommand{\A}{\mathcal{A}}
\newcommand{\B}{\mathcal{B}}
\renewcommand{\C}{\mathcal{C}}
\newcommand{\M}{\mathcal{M}}
\renewcommand{\L}{\mathcal{L}}
\newcommand{\D}{\mathcal{D}}
\newcommand{\N}{\mathcal{N}}

\newcommand{\Cs}{\mathscr{C}}
\newcommand{\Ls}{\mathscr{L}}
\newcommand{\Fs}{\mathscr{F}}
\newcommand{\Rs}{\mathscr{R}}
\newcommand{\Ps}{\mathscr{P}}
\newcommand{\As}{\mathscr{A}}
\newcommand{\Bs}{\mathscr{B}}
\newcommand{\Es}{\mathscr{E}}
\newcommand{\Is}{\mathscr{I}}
\newcommand{\Ss}{\mathscr{S}}

\newcommand{\xn}{x_{1},\dots,x_{n}}

\newcommand{\Nat}{\mathbb{N}}
\newcommand{\Int}{\mathbb{Z}}
\newcommand{\Real}{\mathbb{R}}
\newcommand{\Rat}{\mathbb{Q}}

\newcommand{\Dom}{\texttt{dom}}
\newcommand{\Ran}{\texttt{rng}}

\newcommand{\tdeg}{\texttt{deg}_T}
\newcommand{\tzero}{\mathbf{0}}

\newcommand{\da}{\mathbf{a}}
\newcommand{\db}{\mathbf{b}}
\newcommand{\dc}{\mathbf{c}}
\newcommand{\dd}{\mathbf{d}}

\newcommand{\chain}[2]{(#1_{#2})^{\infty}_{#2=0}}

\newcommand{\xs}{overline{x}}
\newcommand{\ys}{overline{y}}
\newcommand{\zs}{overline{z}}

\newcommand{\ol}{\overline}

\newcommand{\ov}[1]{\overline{#1}}
\newcommand{\abs}[1]{\vert{#1}\vert}
\newcommand{\pair}[1]{\langle{#1}\rangle}
\newcommand{\code}[1]{\ulcorner{#1}\urcorner}

\newcommand{\dfv}{\overset{\text{деф}}{\equiv}}
\newcommand{\df}{\stackrel{\text{деф}}{=}}
\newcommand{\dff}{\stackrel{\text{деф}}{\iff}}

\newcommand{\sg}{\texttt{sign}}
\newcommand{\rev}{\texttt{rev}}

\renewcommand{\iff}{\ \Leftrightarrow\ }
\newcommand{\imply}{\ \Rightarrow\ }
\newcommand{\todo}{\ding{45}\ }
\newcommand{\comment}{\texttt{/}\!\texttt{/}\ }
\newcommand*{\blank}{\sqcup}
\newcommand{\val}[1]{\llbracket{#1}\rrbracket}


% \newcommand{\comment}[1]{\texttt{/\!/}\ #1}
\newcommand{\uup}{\upharpoonright\!\upharpoonright}

\newcommand{\strconc}{%
  \mathord{
    \mathchoice
    {\raisebox{1ex}{\scalebox{.7}{$\frown$}}}
    {\raisebox{1ex}{\scalebox{.7}{$\frown$}}}
    {\raisebox{.7ex}{\scalebox{.5}{$\frown$}}}
    {\raisebox{.7ex}{\scalebox{.5}{$\frown$}}}
  }
}