Context-Sensitive Languages

1. The closure of the context-sensitive languages under complement
   1. Lance Fortnow’s page, describing four relatively recent results in automata theory
   2. The citation for the award of the 1995 Gödel prize to Neil Immerman and Róbert Szelepcsényi for proving that nondeterministic space complexity classes are closed under complement. The fact that the context-sensitive languages are closed under complement follows from that result.
   3. Neil Immerman’s page, with links to his papers
   4. Róbert Szelepcsényi's page

Feature and Attribute Grammars

1. A good introduction to attribute grammars by Hantao Zhang
2. A good survey of attribute grammars, their use in compiler generators, and issues that arise in checking for circularity
3. Elegant: A programming language defined using attribute grammars and offering attribute grammars as tools for programmers
4. A very short survey of feature grammars used by linguists
5. Grammars plus constraints describe product families: an example from the AHEAD tool suite

Lindenmayer systems

1. Descriptions of the formalism and interpreters for it
   1. Mike’s Weblog, compares L-systems to Markov algorithms and semi-Thue systems and describes an interpreter
   2. An Introduction to Lindenmayer Systems, by Gabriela Ochoa
   3. David Wright’s tutorial
   4. An article on D0L sequences From Springer’s Encyclopedia of Mathematics, describes the impact of these systems on some areas of mathematics
   5. Lindyhop, An L-system simulator written in Java
2. An L-system that describes the Fibonacci series models limericks and ragtime, an essay by Kevin Jones
3. Fibonnaci Numbers
   1. Fibonnaci Numbers and Nature
4. Turtle graphics
   1. Wikipedia’s page
5. Fractals
   1. Sierpinski triangles
      1. An applet for watching Sierpinski triangles grow
      2. Wikipedia’s page
6. Context-sensitive L-systems
   1. A simple example of a context-sensitive L-system from David Wright’s tutorial
7. Using L-systems to define plant structure
   1. A very simple L-system can generate a quite natural looking tree.
   2. The Algorithmic Beauty of Plants, a book by Przemyslaw Prusinkiewicz
   3. The Algorithmic Botany site at the University of Calgary
   4. A Sketchbook on L-Systems
8. Using L-systems to compose music
9. Using L-systems in architectural design
   1. One approach

Context-Free Languages