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This wonderful book..... March 13, 2011 10:51AM |
Registered: 8 years ago Posts: 7 Rating: 0 |

To however cares:

I registered for Formal Logic 4, as I really enjoyed Formal Logic 1, 2 and 3.

I have had a 4 year gap since Formal Logic 3, so to get back into things, I started reading rough Appendix A of our prescribed book - which summarizes what we should know.

So I get to page 289 and read the following:

"To show that a set S is a subset of another set T, choose an arbitrary element x e S, and show x e T."

For those who cannot see the problem with this:

Imagine a world where S = {x, y, z} and T = {z, w, v} - Obviously S is not a subset of T, but according to this wonderful book (in its 6th printing), we can actually prove it is, that is right folks, S can be proved to be a subset of T.

We just need to pick an arbitrary element of S and show it is also an element of T, so I ask an average Joe to pick a element: Joe picks Z, because when Joe hears or sees z he thinks of a Zebra, so we take z and we look for it in T, and there it is! S is now officially a subset of T!! (or is it????)

Now if this was an exam paper, would it get marked wrong or right if I give this proof?????? Formal logic??? Really??

Would it cost me money, time and patience to get a remark, would the person remarking it, see and understand my point? Would I be able to tell them the problem? The answer is simply, at the end of the day, we the student suffer, because we have bought an expensive book that has more errata and still more un-found problems in it than there's water in the see!

Enjoy COS407C!

I registered for Formal Logic 4, as I really enjoyed Formal Logic 1, 2 and 3.

I have had a 4 year gap since Formal Logic 3, so to get back into things, I started reading rough Appendix A of our prescribed book - which summarizes what we should know.

So I get to page 289 and read the following:

"To show that a set S is a subset of another set T, choose an arbitrary element x e S, and show x e T."

For those who cannot see the problem with this:

Imagine a world where S = {x, y, z} and T = {z, w, v} - Obviously S is not a subset of T, but according to this wonderful book (in its 6th printing), we can actually prove it is, that is right folks, S can be proved to be a subset of T.

We just need to pick an arbitrary element of S and show it is also an element of T, so I ask an average Joe to pick a element: Joe picks Z, because when Joe hears or sees z he thinks of a Zebra, so we take z and we look for it in T, and there it is! S is now officially a subset of T!! (or is it????)

Now if this was an exam paper, would it get marked wrong or right if I give this proof?????? Formal logic??? Really??

Would it cost me money, time and patience to get a remark, would the person remarking it, see and understand my point? Would I be able to tell them the problem? The answer is simply, at the end of the day, we the student suffer, because we have bought an expensive book that has more errata and still more un-found problems in it than there's water in the see!

Enjoy COS407C!

Re: This wonderful book..... March 29, 2011 08:05PM |
Registered: 13 years ago Posts: 287 Rating: 0 |

Hi jlc,

I studied this module last year and I found the textbook next to useless. It was very difficult to read and deliberately incomprehensible at times. I would say in some pages the author went out of his way to explain things that was irrelevant to the course and provided didn't bother explaining the concepts in a fashion that could be easily understood. In many cases I was left guessing what the steps were and how he got to those steps. I would suggest that you use the text book only for the tables that you need to memorise only. Reading anything else is just a waste of time. Its almost like a terrible maths textbook and I'm not sure why it is this way. If I could attend lectures this module would have been substantially less frustrating.

I studied this module last year and I found the textbook next to useless. It was very difficult to read and deliberately incomprehensible at times. I would say in some pages the author went out of his way to explain things that was irrelevant to the course and provided didn't bother explaining the concepts in a fashion that could be easily understood. In many cases I was left guessing what the steps were and how he got to those steps. I would suggest that you use the text book only for the tables that you need to memorise only. Reading anything else is just a waste of time. Its almost like a terrible maths textbook and I'm not sure why it is this way. If I could attend lectures this module would have been substantially less frustrating.

Re: This wonderful book..... April 09, 2011 02:46PM |
Registered: 8 years ago Posts: 7 Rating: 0 |

There is light out there, another person who can see that this textbook is utter nonsense. Even worse is, I have e-mailed this lecturer multiple times about things in this book which just cannot be right, I even resorted to sending the same e-mail multiple times without a response.

I cannot believe that authors and lecturers get away with such nonsense! When I had Formal Logic 1, 2 and 3 there was a female lecturer handling the logic courses - i just cannot remember her name, but she was excellent! Always responded and the textbooks she chose was clear, to the point and not misleading in any way like this stupid book.

Lecturer responsible for COS407-C, I dare you to comment on this, because you are shining in your absence!

I cannot believe that authors and lecturers get away with such nonsense! When I had Formal Logic 1, 2 and 3 there was a female lecturer handling the logic courses - i just cannot remember her name, but she was excellent! Always responded and the textbooks she chose was clear, to the point and not misleading in any way like this stupid book.

Lecturer responsible for COS407-C, I dare you to comment on this, because you are shining in your absence!

Re: This wonderful book..... April 11, 2011 04:45PM |
Registered: 13 years ago Posts: 177 Rating: 0 |

Re: This wonderful book..... April 15, 2011 11:38AM |
Registered: 7 years ago Posts: 1 Rating: 0 |

Here's what you want to do: "choose an arbitrary element q e S, and show q e T" (I'm calling it q so it wont get mistaken for the x that is in S)

With this: S = {x, y, z} and T = {z, w, v}

Ok, so because the element q is arbitrary, you can't know for sure that it is z, and because the sets are small I can just list all the possibilities:

If q=x it is not in T

If q=y it is not in T

If q=z it is in T

q e T only if it is z, but we can't know that

So an arbitrary element q e S will not always be in T, and S is not a subset of T.

Typically the set is described by some formula or definition and when you choose the arb element you will only know the formula

You can probably also state the proof as "for each and every q e S, show that q e T", the thing is just in most cases the sets are infinite and you cant deal with every member individually

Does that help?

With this: S = {x, y, z} and T = {z, w, v}

Ok, so because the element q is arbitrary, you can't know for sure that it is z, and because the sets are small I can just list all the possibilities:

If q=x it is not in T

If q=y it is not in T

If q=z it is in T

q e T only if it is z, but we can't know that

So an arbitrary element q e S will not always be in T, and S is not a subset of T.

Typically the set is described by some formula or definition and when you choose the arb element you will only know the formula

You can probably also state the proof as "for each and every q e S, show that q e T", the thing is just in most cases the sets are infinite and you cant deal with every member individually

Does that help?

Re: This wonderful book..... April 20, 2011 04:17PM |
Registered: 7 years ago Posts: 5 Rating: 0 |

Re: This wonderful book..... June 01, 2011 12:54PM |
Registered: 7 years ago Posts: 1 Rating: 0 |

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