\begin{align}
    L  & = \lim_{|x| \to \infty}\ {{\cos {1 \over x} \cdot  {-1 \over x^2}}\over {-1 \over x^2}} \\
    & = \lim_{|x| \to \infty} {\cos{1 \over x}} \cdot {-1 \over x^2} \cdot {x^2 \over -1} \\
    & = \cos{1 \over \infty} = \cos{\ 0} = 1
\end{align}
\begin{alignat}{2}
    L  & = \lim_{|x| \to \infty}\ {{\cos {1 \over x} \cdot  {-1 \over x^2}}\over {-1 \over x^2}} &\quad& \text{by me ö} \\
    & = \lim_{|x| \to \infty} {\cos{1 \over x}} \cdot {-1 \over x^2} \cdot {x^2 \over -1} && \text{by him} \\
    & = \cos{1 \over \infty} = \cos{\ 0} = 1 && \text{Axiom 3}
\end{alignat}
Foo
\bigl( \begin{smallmatrix}
  a&b\\ c&d
\end{smallmatrix} \bigr)$
Bar
Foo Bar
 A \xleftarrow{n+\mu-1} B \xrightarrow[T]{n\pm i-1} C
2^k-\binom{k}{1}2^{k-1}+\binom{k}{2}2^{k-2}

\sideset Bearbeiten

\sideset{_*^*}{_n^'}\prod_a^b

 

More symbols Bearbeiten

\vartriangle   \triangledown   \lozenge   \circledS  
\measuredangle   \nexists   \Bbbk   \backprime  
\blacktriangle   \blacktriangledown   \blacksquare   \blacklozenge  
\bigstar   \sphericalangle   \diagup   \diagdown  
\dotplus   \Cap   \Cup   \barwedge  
\veebar   \doublebarwedge   \boxminus   \boxtimes  
\boxdot   \boxplus   \divideontimes   \ltimes  
\rtimes   \leftthreetimes   \rightthreetimes   \curlywedge  
\curlyvee   \circleddash   \circledast   \circledcirc  
\centerdot   \intercal   \leqq   \leqslant  
\eqslantless   \lessapprox   \approxeq   \lessdot  
\lll   \lessgtr   \lesseqgtr   \lesseqqgtr  
\doteqdot   \risingdotseq   \fallingdotseq   \backsim  
\backsimeq   \subseteqq   \Subset   \preccurlyeq  
\curlyeqprec   \precsim   \precapprox   \vartriangleleft  
\Vvdash   \bumpeq   \Bumpeq   \geqq  
\geqslant   \eqslantgtr   \gtrsim   \gtrapprox  
\eqsim   \gtrdot   \ggg   \gtrless  
\gtreqless   \gtreqqless   \eqcirc   \circeq  
\triangleq   \thicksim   \thickapprox   \supseteqq  
\Supset   \succcurlyeq   \curlyeqsucc   \succsim  
\succapprox   \vartriangleright   \shortmid   \shortparallel  
\between   \pitchfork   \varpropto   \blacktriangleleft  
\therefore   \backepsilon   \blacktriangleright   \because  
\nleqslant   \nleqq   \lneq   \lneqq  
\lvertneqq   \lnsim   \lnapprox   \nprec  
\npreceq   \precneqq   \precnsim   \precnapprox  
\nsim   \nshortmid   \nvdash   \nVdash  
\ntriangleleft   \ntrianglelefteq   \nsubseteq   \nsubseteqq  
\varsubsetneq   \subsetneqq   \varsubsetneqq   \ngtr  
\ngeqslant   \ngeqq   \gneq   \gneqq  
\gvertneqq   \gnsim   \gnapprox   \nsucc  
\nsucceq   \succneqq   \succnsim   \succnapprox  
\ncong   \nshortparallel   \nparallel   \nvDash  
\nVDash   \ntriangleright   \ntrianglerighteq   \nsupseteq  
\nsupseteqq   \varsupsetneq   \supsetneqq   \varsupsetneqq  
\leftleftarrows   \leftrightarrows   \Lleftarrow   \leftarrowtail  
\looparrowleft   \leftrightharpoons   \curvearrowleft   \circlearrowleft  
\Lsh   \upuparrows   \rightrightarrows   \rightleftarrows  
\Rrightarrow   \rightarrowtail   \looparrowright   \curvearrowright  
\circlearrowright   \Rsh   \downdownarrows   \multimap  
\leftrightsquigarrow   \rightsquigarrow   \nLeftarrow   \nleftrightarrow  
\nRightarrow   \nLeftrightarrow