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


Inset hierarchy:
                                   
                                   MathInset   
                                (abstract base)

                         /            |             \

              Dim                  Char                   MacroArg
         (thing that need       (for things formerly 
          the width_/ascent_     known as characters) 
          /descent_ cache)
        
          /             \

       Nest              Dots  Func  Space  Symbol Bigop Noglyph
  (for thing with      
   nested content)     

        |         \

      Grid        Decoration   Delim   Frac  Macro  Root  Script  Sqrt

      /   \

 Array     "Matrix"
         (base for eqnarray/align/...)



There are only two "real LyXInsets" in here:

Formula       - containing a pointer to a  MathMatrixInset (a misnomer...)
FormulaMacro  - containing a pointer to a  MathMacroTemplate