anchor.diff:  \large,{\large AaBb123}
   \lbrace,
   \lceil,
  -\ldots,
   \leadsto,
   \left,\left\lbrace \frac ab, c \right\rbrace
   \leftarrow,
  
positive.code: \smallfrown,
  \smallint,
  \smallsmile,
  \smash,\sqrt{\smash{7}\vphantom{\frac ab}}
  \Space,a\Space{5px}{4ex}{2ex}^b_c d
  \spadesuit,
  \sqcap,
  
negative.code: #,\def\specialFrac#1#2{\frac{x + #1}{y + #2}}
  %,%this is a single-line comment
  &,"\begin{matrix}
  a & b\cr
  c & d
  \end{matrix}"
  ^,x^i
  _,x_i
  {,\{
  