I don't really get the point in learning all these cool formal techniques and elimination rules for several months,

only to be given 2 questions which are insanely difficult to answer. (Add sarcasm as necessary)

The exam didn't truly test a student on his knowledge or ability to apply what they have learnt.

I feel really disappointed. I really enjoyed doing this course and the assignments.

But the exam was really unfitting.There are so many cool ways to test the syllabus and Tarski's world stuff.

This is just my opinion.

(and i doubt they will release stats)]]>

Well, at least we're done with this one, now its COS201, then COS2213, then its holiday.]]>

Edit: I wrote 2 papers today by the way. Brain is broken. :(]]>

Some modules require that you think for yourself, apply the theory, and understand why some rules are made...NOT just do examples so you are capable of doing problems

That's pretty tricky imo, considering ALL the examples in the assigmnet have you assuming something next to the little block thing in your subproof first.

Thanks a lot man!]]>

I wish they'd give us proper examples in the study guide, because seeing these things in the exam for the first time is really silly. Half of this course is guesswork thanks to the poor study guide. I mean at least give us solutions to the textbook questions.]]>

Funny(b) v Clever(b) v Pretty(b)

as well as

(Funny(b) v Clever(b)) -> ~Angry(b)

both are sited by Universal Elimination

Now, clearly we have to prove by case (3 in fact)

Sub proof one ( Assume Funny(b)) should not be a problem (you wish to get ~Angry(b) as end result)

Sub proof two (Assume Clever(b)) should also be easy (you wish to get ~Angry(b) as end result)

Sub proof three is the tricky one..

Assume Pretty(b)

Now make a new sub proof under this one and assume Angry(b).

Now, you can state Angry(b) & Pretty(b) (Conditional Intro from Pretty(b) and Angry(b))

Since we now have Angry(b) & Pretty(b), we can state Ex(Angry(x) & Pretty(x)), but guess what, this contradicts Premise 1, so indicate contradiction and state your two lines, end the sub proof and now state ~Angry(b) with rule ~Intro and state the lines of the sub proof you just finished. Now, you should see that you have three cases and all of them ends with ~Angry(b), so end this last case and write ~Angry(b). State as rule Disjunction elimination and state the lines for your disjunction sentence and your three cases. End the sub proof and state Ax ~Angry(x) and state as rule, Universal Intro specifying the lines for your b sub proof

And that's that..]]>

Although you said that it sounded like it might be a biconditional, you did not actually translate it

into FOL using a biconditional but you stated ExEy (Something ->

Something else)â€¦ chances are that if you have an Ex(P->Q) then it is probably wrong..

Here is my take on it, but donâ€™t take my word for it though..

1)

Since Running (Q) is a necessary condition for Winning (P), we must write it in the form P->Q

(P is a sufficient condition for Q but Q is a necessary condition for P, ie, winning is a sufficient

reason for running, but running is a necessary condition to win the race)

2)

Using the term â€œOneâ€, we have to assume that the speaker is generalizing, thus talking about

something that is true of everybody (every person in the domain), thus we will have to use a

universal quantifier (Ax)

3)

Since we want to talk about Early Bird as a race, we have to identify its free variable (earlybird)

in our FOL. We donâ€™t want to introduce it for the first time inside the scope of any of our

quantifiers, so in this case it will be best if we state Race(earlybird) first and once we have done

that, continue writing the rest of our sentence, thus we start our sentence with

Race(earlybird) ^

4)

So, we can write Race(earlybird) ^ Ax(Wins(x,earlybird) ->.........)

5)

What gets me is the part â€œOne runs 30km or more every weekâ€.

Does one write Ey(Runs(x,y) ^ Â¬ LessThan(y,30))

or does one write Ay(Runs(x,y) -> Â¬ LessThan(y,30)).

Runs(x,y) already means x Runs y km every week.

If we look at the Universal form, we may interpret it as saying â€œNo kilometres that one runs

every week are less than 30â€.

If we look at the Existential form, we may interpret it as saying â€œSome kilometres that one runs

every week are not less than 30â€

From these interpretations, it would seem that we have to go the Universal route, thus

6)

Race(earlybird) ^ Ax(Wins(x,earlybird) -> Ay(Runs(x,y) -> Â¬ LessThan(y,30)))

Is that the correct way of translating the particular sentence from English to FOL? I donâ€™t knowâ€¦

the study guide doesnâ€™t give enough guidance so I cannot say yes with absolute certainty]]>

Since the premise is NOT Ex (Angry(x) ^ Pretty(x)), what should our first subproof be? Is it NOT(Angry(e) ^ Pretty(e))? Is it NOT Angry(e) OR NOT Pretty(e).

The negation in the premise is really throwing me off. I can't find a simlar problem in teh textbook or study guide...don't know what to do with it!]]>

Been working through May's exam, and was wondering something.

Question 1(ii) says "One can only win the Early Bird road race if one runs 30 km or more every week."

Do we interpret this as an "If and only if" statement? I.e. One can win the Early Bird road race if and only if one runs 30km or more every week?

Cause then I see it as Ex Ey ((Race(early bird) ^ Win(x,early bird)) -> Runs(x,y) ^ NOT LessThan(y,30))

Am I right in assuming this or am I reading too much into the sentence?

PS I don't know how to make all the symbols in the forum but I think you get the general idea.]]>

> The book is actually not that bad (and if it

> wasnâ€™t for the software, I would not be able to

> pass this subject at all, no matter what the

> Tutorial letters are saying - There just isnâ€™t

> enough guidance in the Tutorial letters for some

> of us â€œslower folksâ€).

> The main problem is that you need to spend a lot

> of time working through the text book and do as

> much exercises as you can. The secondary problem

> (as Iâ€™ve mentioned) is that the study guide

> isnâ€™t providing enough information, more so for

> those of us that are working (more sample

> questions with solutions etc. would have helped).

I couldn't agree more. I'm having a heck of a time with the formal proofs, because they assume so much from you. The study guide has like 1 or 2 examples (if that) per chapter. It's just not good enough. With this kind of thing you need as much practice as possible, but how can I practice if I don't know have any examples to work with? Sure, the software helps you to an extent, but it really only assists in checking if you are right, not in guiding you to the right solution.]]>

1) Hardly any worked examples

2) Stuff like "See if you can figure out where you went wrong."

3) No answers in the back of the book for guidance]]>

Will be much appreciated.

46089594 at mylife dot unisa dot ac dot za]]>