k dude……

i have a doubt in toc…plz any one help me out..how can we judge with the help of parse tree whether grammar is finite aur infinite….there is theorem for it…..plz guys help me if you knoe….

Why is the topic name ‘Gate 2010 Computer Science Doubts’ ?
It should be ‘Gate 2012’ na? Must be typing mistake. Please correct it.

friends can anyone tell me where to find subject wise papers for gate?like question paper with operating system question?

@Sampath,
Instead of going for Subject wise GATE papers, its better to go through actual GATE papers and collect questions
Advs :
1. There are printing mistakes in other material that may waste valuable time.
2. You will also come to know the sequence of questions subject wise, how they are grouped together n all. (This matters a lot in final 3 hrs since we are solving questions from all the subject in that time)

Other than this, there are many coaching institutes which provide subject wise question papers (sometimes topic wise too!).

Best resources to find the practice questions :
1. Previous year GATE question papers.
2. Standard book exercises given after chapters.
(e.g. Peter Linz’s TOC book has very good exercise collection.)

@ Manisha Pandey may be not got it correctly, but if there is any non-terminal variable at the leaf node of the parse tree then d language is infinite else finite…

@ Manisha, to know if some grammer is finite or infinite, you jst need to have a look at the production rules, if there is any recursive production then the grammer is infinite. for example a production like..
S—> Sab|a
You can producing S again and againby this production infinitely.
Hope i answered your question. 🙂

Manisha Pandey
no need of parse tree
just check whether it has any recursive production rule as suggested by Lorin Ahmed
or just draw finite automata of that grammar n if it contains any loop or self loop then the language generated by grammar is infinite