Regards]]>

I just wanted to know if anyone has any extra past exam papers for this module other than last years.

If you do please contact me on chettyn@sabc.co.za

Thanks

NIRI]]>

Would just like to know if anyone has previous papers for this module. Would just like to see how questions are asked. Will appreciate any assistance.

Thanx.

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M can globally fail <>(a -> b) -> (<>a -> <>b) only if there exists some x in G such that M satisfies <>(a -> b) at x and fails to satisfy (<>a -> <>b) at x. And M can fail to satisfy (<>a -> <>b) at x only by satisfying <>a at x but not satisfying <>b at x. And M fails to satisfy <>b at x only if it fails to satisfy Ã‚Â¬[]Ã‚Â¬b at x. i.e. it satisfies []Ã‚Â¬b at x. And M satisfies []Ã‚Â¬b only if for all y in G with (x,y) in R such that M does not satisfy b at y.

This cannot be because <>(a -> b) is satisfied at x. i.e. Ã‚Â¬[]Ã‚Â¬(a -> b) is satisfied at x. i.e. []Ã‚Â¬(a -> b) fails to be satisfied by M at x and since y is accessible from x; Ã‚Â¬(a -> b) fails to be satisfied at y. i.e. a -> b is satisfied at y. Similarly, since <>a is satisfied at x, a is satisfied at y. Therefore b must be satisfied by y.

so the sentence must be globally true.

I know this to be wrong - I'm just not sure why.]]>

I'm having a little difficulty understanding the solution to ex 3.3.1(e) the last wff, specifically how to quantifiers interact.

why is the order not interchangeable? I believe this hinges on the following question. Why can I not use an assignment v" that differs from v' at most on x2 where v' differs from v at most on x1 (v being the arbitrary assignment in which context we're trying to satisfy alpha)? i.e., in the solution, why is u said to be like v and not v'?

clearly there is a reason or the quantifiers would be interchangeable - I just can't see it.

Please help,

-Jason.]]>

Do any of you have concerns regarding the marking of assignment 1? I have just received my assignment back and it seems that marks are being deducted in an injustified manner. Also I see that if your proof or argument is not according to the lecturers "taste" you are penalised heavily- even though the argument is logical and sound. Is it just me???

Regards]]>

Anyways - just felt like sharing a moment.

Cheers.

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