Inset 'Xyz' is implemented by 'MathXyzInset' in 'math_xyzinset.[hC]'


Inset hierarchy:

                                   MathInset
                                (abstract base)

                         /            |               \

              Dim                  Char               Symbol, Space, ...
         (thing that need       (for things formerly
          the width_/ascent_     known as characters)
          /descent_ cache)

          /             \

       Nest              Dots,  Func, ...
  (for thing with
   nested content)

        |         \

      Grid        Decoration   Delim   Frac  Macro  Root  Script  Sqrt

      /   \

 Array    Hull
         (base for eqnarray/align/...)