* L-system
** L-system is a rewriting system and a type of formal grammar.
** The purpose of l-system is representation of realistic models of natural patterns.
** For an example, see 'examples/l-system-example.lisp'.
** At the moment you can use it like:
   Lindenmayer's original L-system
   Parametric grammars
   Context sensitive grammars
** It is based on [[https://en.wikipedia.org/wiki/L-system#Variations][Wikipedia link]].