Editing L-system (section)

{{Short description|Rewriting system and type of formal grammar}}
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[[File:Dragon trees.jpg|thumb|upright=1.5|L-system trees form realistic models of natural patterns]]

An '''L-system''' or '''Lindenmayer system''' is a [[wikt:parallel|parallel]] [[rewriting system]] and a type of [[formal grammar]]. An L-system consists of an [[alphabet]] of symbols that can be used to make [[string (computer science)|string]]s, a collection of [[Production (computer science)|production rule]]s that expand each symbol into some larger string of symbols, an initial "[[axiom]]" string from which to begin construction, and a mechanism for translating the generated strings into geometric structures. L-systems were introduced and developed in 1968 by [[Aristid Lindenmayer]], a Hungarian theoretical [[biologist]] and [[botanist]] at the [[Utrecht University|University of Utrecht]].<ref>{{Cite journal|last=Lindenmayer|first=Aristid|date=March 1968|title=Mathematical models for cellular interactions in development II. Simple and branching filaments with two-sided inputs|journal=Journal of Theoretical Biology|volume=18|issue=3|pages=300–315|doi=10.1016/0022-5193(68)90080-5|pmid=5659072|bibcode=1968JThBi..18..300L|issn=0022-5193}}</ref> Lindenmayer used L-systems to describe the behaviour of plant cells and to model the growth processes of [[plant development]]. L-systems have also been used to model the morphology of a variety of organisms<ref>Grzegorz Rozenberg and Arto Salomaa. The mathematical theory of L systems (Academic Press, New York, 1980). {{ISBN|0-12-597140-0}}</ref> and can be used to generate self-similar [[fractal]]s.