A property of random context picture grammars
β Scribed by Andries van der Walt; Sigrid Ewert
- Publisher
- Elsevier Science
- Year
- 2003
- Tongue
- English
- Weight
- 211 KB
- Volume
- 301
- Category
- Article
- ISSN
- 0304-3975
No coin nor oath required. For personal study only.
β¦ Synopsis
We use random context picture grammers to generate pictures through successive reΓΏnement.
The productions of such a grammar are context free, but their application is regulated by context randomly distributed in the developing picture. Grammars using this relatively weak context often succeed where context-free grammars fail, e.g., in generating the typical iteration sequence of the SierpiΓ nski carpet. On the other hand, it proved possible to develop iteration theorems for three subclasses of these grammars; ΓΏnding necessary conditions is problematic in the case of most models of context-free picture grammars with context-sensing ability, since they consider a variable and its context as a connected unit.
We present a property of all picture sets generated with random context picture grammers, and then construct a picture set that does not belong to this class.
π SIMILAR VOLUMES
A practical method is presented for the automatic generation of a non-recursive context-free grammar (cfg) from a set of strings that the cfg is required to be capable of producing. The method is efficient in computing time by comparison with enumerative methods.
A homogeneous production has its left-hand side formed by a non-empty string of identical nonterminals. A phrase-structure grammar is homogeneous if each of its productions is homogeneous. The present paper discusses the reduction of homogeneous grammars with respect to the number of non-context-fre