On computational complexity of contextual languages

On Computational Complexity of Contextual Languages

We consider the following restriction of internal contextual grammars, called local: in any derivation in a grammar, after applying a context, further contexts can be added only inside of or at most adjacent to the previous ones. We further consider a natural restriction of this derivation mode by requiring that no superword of the word considered as selector can be used as selector. We investi...

the effect of task complexity on lexical complexity and grammatical accuracy of efl learners’ argumentative writing

بر اساس فرضیه شناخت رابینسون (2001 و 2003 و 2005) و مدل ظرفیت توجه محدود اسکهان (1998)، این تحقیق تاثیر پیچیدگی تکلیف را بر پیچیدگی واژگان و صحت گرامری نوشتار مباحثه ای 60 نفر از دانشجویان زبان انگلیسی بررسی کرد. میزان پیچیدگی تکلیف از طریق فاکتورهای پراکندگی-منابع تعیین شد. همه ی شرکت کنندگان به صورت نیمه تصادفی به یکی از سه گروه: (1) گروه موضوع، (2) گروه موضوع + اندیشه و (3) گروه موضوع + اندی...

Computational Complexity of Controlled Natural Languages

On the computational complexity of imperative programming languages

Two restricted imperative programming languages are considered: One is a slight modification of a loop language studied intensively in the literature, the other is a stack programming language over an arbitrary but fixed alphabet, supporting a suitable loop concept over stacks. The paper presents a purely syntactical method for analysing the impact of nesting loops on the running time. This giv...

On the Computational Complexity of Synchronized Context-Free Languages

We introduce counter synchronized context-free grammars and investigate their generative power. It turns out that the family of counter synchronized context-free languages is a proper superset of the family of context-free languages and is strictly contained in the family of synchronized context-free languages. Moreover, we establish the space and time complexity of the fixed membership, the ge...