\documentclass{article}

\usepackage{stmaryrd}

\begin{document}
\[
a \Ydown b \quad a \Yleft b \quad a \Yright b \quad a \Yup b
\]
\[
a \baro b \quad a \bbslash b \quad a \binampersand b \quad a \bindnasrepma b
\]
\[
a \boxast b \quad a \boxbar b \quad a \boxbox b \quad a \boxbslash b \quad a \boxcircle b \quad a \boxdot b \quad a \boxempty b \quad a \boxslash b
\]
\[
a \curlyveedownarrow b \quad a \curlyveeuparrow b \quad a \curlywedgedownarrow b \quad a \curlywedgeuparrow b
\]
\[
a \fatbslash b \quad a \fatsemi b \quad a \fatslash b \quad a \interleave b
\]
\[
a \leftslice b \quad a \merge b \quad a \minuso b \quad a \moo b \quad a \nplus b
\]
\[
a \obar b \quad a \oblong b \quad a \obslash b \quad a \ogreaterthan b \quad a \olessthan b \quad a \ovee b \quad a \owedge b
%\quad a \oast b \quad a \ocircle b
\]
\[
a \rightslice b \quad a \sslash b \quad a \talloblong b \quad a \varbigcirc b \quad a \varcurlyvee b \quad a \varcurlywedge b
\]
\[
a \varoast b \quad a \varobar b \quad a \varobslash b \quad a \varocircle b \quad a \varodot b \quad a \varogreaterthan b \quad a \varolessthan b
\]
\[
a \varominus b \quad a \varoplus b \quad a \varoslash b \quad a \varotimes b \quad a \varovee b \quad a \varowedge b \quad a \vartimes b
\]
\[
\bigbox \quad \bigcurlywedge \quad \bigcurlyvee \quad \biginterleave \quad \bignplus \quad \bigparallel \quad \bigsqcap \quad \bigtriangledown \quad \bigtriangleup
\]

\[\textstyle
\bigbox \quad \bigcurlywedge \quad \bigcurlyvee \quad \biginterleave \quad \bignplus \quad \bigparallel \quad \bigsqcap \quad \bigtriangledown \quad \bigtriangleup
\]

\[ {\displaystyle \bignplus}\qquad {\textstyle \bignplus}\qquad {\scriptstyle \bignplus}\qquad
{\scriptscriptstyle \bignplus}\]

\[
\inplus \quad \niplus \quad \ntrianglelefteqslant \quad \ntrianglerighteqslant \quad \trianglelefteqslant \quad \trianglerighteqslant
\]
\[
a \subsetplus b \quad a \subsetpluseq b \quad a \supsetplus b \quad a \supsetpluseq b
\]
\[
a \mapsfromchar b \quad
a \mapsfrom b \quad
a \Mapsfromchar b \quad
a \Mapsfrom b \quad
a \longmapsfrom b \quad
a \Longmapsfrom b \quad
\]
\[
a \Mapstochar b \quad
a \Mapsto b \quad
a \Longmapsto b \quad
\]

\[
a \nnearrow b \quad
a \nnwarrow b \quad
a \ssearrow b \quad
a \sswarrow b
\]

\[
a \leftarrowtriangle b \quad
a \rightarrowtriangle b \quad
a \leftrightarrowtriangle b \quad
a \leftrightarroweq b \quad
a \lightning b
\]

\[
a \shortdownarrow b \quad
a \shortleftarrow b \quad
a \shortrightarrow b \quad
a \shortuparrow b
\]
\[
a \arrownot b\quad
a \longarrownot b \quad
a \Arrownot b \quad
a \Longarrownot b
\]

\[
\Lbag 42 \Rbag \quad
\lbag 42 \rbag \quad
\]
\[
\llbracket 42 \rrbracket \quad
\llfloor 42 \rrfloor \quad
\llceil 42 \rrceil \quad
\llparenthesis 42 \rrparenthesis
\]
\varcopyright
\end{document}