I have searched online and I cant find the address for the Tongaat exam venue? I will be writing there this year, could you please give me the address? Thanks!]]>

Thank heavens I got a sup. :)]]>

I did the second assignment and got almost nothing.

My year mark also brought me down with 5%.

Maybe there's a calculation error?

If I do the math it should of only been down by 3.7%]]>

Email me on 45755124@mylife.unisa.ac.za or reply to this post.]]>

Regards

Rutendo.]]>

May I ask for past material for the following subject, I will be taking these modules in 2012. Please kindly send to sedeya@gmail.com

(COS2621) Computer organization (Computer Science 221)

(COS2661) Formal logic 2 (Computer Science 261)

(INF3705) Advanced systems development (Information Systems 305)

(COS3701) Theory of computer science 3 (Computer Science 301)

(COS3711) Advanced programming (Computer Science 311)

(COS3721) Operating systems and architecture (Computer Science 321)

(COS3712) Computer graphics (Computer Science 340)

(COS3761) Formal logic 3 (Computer Science 361)

Thanks in advance.

Regards

Rutendo.]]>

my thoughts herewith on the question 3 for pumping lemmas in 2006 exam paper.

They ask to prove that a

So we put down the whole assumption of L is context free and thus has a CFG in CNF with p live productions and a word w with length(w) > 2

thus we can apply the pumping lemma and thus the word w can be devided into uvxyz (5 parts) such that uv

such that

length(x) > 0

Length(v) + length(y) > 0

Length(vxy) <= 2

i choose

i choose n to be 2

NOw we take this options where vxy might be.

1. It might be in a single clump of a or b

if so and if then pumped to vvxyy or more, a will be increased at one clump, but not in the others. This would result in the relationship between the first a and the second a to become null and void.

in other words before pumping we had a value of n / n+3 (or rather 2

after pumping this value will no longer be the same, because the first 2

Same wouldf apply to any of the other clumps.

2. THe other option is the vxy falls over part of a's and part of b's (straddles as the book says). If so, taking the first two sets of a's and b's, when pumped it would increase either the a's or the b's or both. Again messing up the value relantioship between these a's and b's and the others.

hence all cases are contradictory to assumption.

Does this make sense.?

it seems easier with a

just have some thoughts / questions on the first part of the work. you might find another post after this touching on other topics.

please give your input.

The Theorem that allows you to see if language is finite / infinite:

My understanding according to theorem 43 and 44.

0. make sure is isn't nullable, byt reverse working the NULL sign to see if S ever gets to NULL.

1. make sure its in CNF

2. remove unproductive terminals (ones that dont go to nonterminals ever -- ie. N =>* n - it will never reach n)

3. Find the useful ones by blue paint. The we know which Non terminals take part in forming words. Remember the useful ones;

4. show that the useful non terminals are actually usefull by substitution

5. Now mark each of the useful NON Terminals as FUNNYX, and see if its self embedded.

IF USEFULL and SELF EMBEDDED then L = INFINITE

Missing anything]]>

If anyone has past papers or other useful information about this module please mail it to me at roderick.midgley@gmail.com.]]>

It's this kind of proof from assertion A to assertion B ... A -> B (fill in an A and B)

Followed by B -> A.

So in the end you should have A <-> B.

(The basics are old stuff, in other words.)

And memory deserts me there for now.]]>

Its seems pretty easy to show that a language(s) L1 and L2 are closed under +, product and * (kleene closure),

but in our 2006 exam paprer they ask

1. Show the language L1L2 and

2. prove that it is correct (two way proof).

I need to know what they want from number 2. The number 1 is the proof in Cohen.]]>

I know there are videos on Youtube uploaded by CoderIsland that are useful to this subject.

Can somebody tell me which ones they are?

Thanks]]>

get the following

Fatal internal error handling request:

Target exception of class java.lang.NullPointerException

Successive lines until stack trace show causes progressing to exception site:

java.lang.NullPointerException

when clicking on official Study Material link...

still awaiting reply from myunisa support...]]>

Now my proposal is: can you please indicate if you need tutorials so that I can get back to that lady with a number of those who need help like me. The sooner ,the better. its only R150 to enroll for tutorials per 3 modules.

thanks]]>