Pure 2D picture grammars and languages
نویسندگان
چکیده
A new syntactic model, called pure 2D context-free grammar (P2DCFG), is introduced based on the notion of pure context-free string grammar. The rectangular picture generative power of this 2D grammar model is investigated. Certain closure properties are obtained. An analogue of this 2D grammar model called pure 2D hexagonal context-free grammar (P2DHCFG) is also considered to generate hexagonal picture arrays on triangular grids.
منابع مشابه
Comparison results of 2D Monogenic Pure Context Free Picture Grammars with other relating models
Picture languages generated by array grammars or accepted by array automata have been studied by researchers and various models have been proposed in the literature, motivated by problems arising in the framework of syntactic methods of pattern recognition and image processing. The notion of Pure 2D Picture Grammars, generating rectangular picture arrays of symbols is already there in the liter...
متن کاملOn the Complexity of pure 2D Context-free Grammars
Picture languages generalize classical string languages to two-dimensional arrays. Several approaches have been proposed during the years; consequently, a general classification and a detailed comparison of the classes proposed turns to be necessary. We studied in detail closure properties of (regular) pure 2D context-free grammars (R)P2DCFG [1], and the complexity of the membership problem [2].
متن کاملA Comparative Study on Adjunct Array Token Petri Nets with Some Classes of Array Grammars
Adjunct Array Token Petri Net Structures (AATPNS) are recently introduced rectangular picture generating devices which extended the Array token Petri net Structures. AATPNS generated context free and context sensitive kolam array languages and tabled 0L/1L languages. In this paper we compare AATPNS with some simple and expressive picture grammar models like extended pure 2D context-free grammar...
متن کاملOn Some Classes of 2D Languages and Their Relations
Many formal models have been proposed to recognize or to generate two-dimensional words. In this paper, we focus our analysis on (regular) pure 2D context-free grammars, regional tile grammars and Pr̊uša grammars, showing that nevertheless they have been proposed as a generalization of string context free grammars their expressiveness is different. This work refines the relationship among the cl...
متن کاملPicture languages: Tiling systems versus tile rewriting grammars
Two formal models of pictures, i.e., 2D languages are compared: Tiling Systems and Tile Rewriting Grammars, which resp. extend to 2D the Regular and Context-Free languages. Two results extending classical language properties into 2D are proved. First, non-recursive TRG coincide with TS. Second, non-self-embedding TRG are suitably defined as corner grammars, showing that they generate TS languag...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Discrete Applied Mathematics
دوره 157 شماره
صفحات -
تاریخ انتشار 2009