Help with a bijection proof involving sets

In summary, the conversation revolves around a question in a pdf document that asks for a proof involving cardinality of sets. The third question is causing problems for the person and they are unsure if there is a typo in the question or not. They discuss the definition of bijection and provide an example with sets of different cardinalities. The conclusion of the question is proven to be false with a counterexample involving a set with larger cardinality. The person is still unsure if the question can be proven or not.
  • #71
The class is Automata, Complexity, and Compatability. I'm a CPSC Information Security and Assurance major, and this is counts as an elective that I need to take to graduate.
 
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  • #72
EonsNearby said:
The class is Automata, Complexity, and Compatability. I'm a CPSC Information Security and Assurance major, and this is counts as an elective that I need to take to graduate.

That's pretty interesting stuff. Should be fun. You'll definitely see some formal proofs.
 
  • #73
Well, I'm hoping it is better than this rocky stuff, because this problem has not been kind to my sleep schedule.
 
  • #74
I am also in this class and just recently started following the discussion, which is why I haven't contributed anything. In response to the earlier post about:
"I would also ask him if he expects people to already know how to do these kinds of proofs; or if you are expected to learn that set of skills in the course." (I don't really know how to do the quoting thing y'all were doing earlier so I just did it this way). I really have no idea how to do these proofs and would have had no idea where to start if EonsNearby hadn't asked the questions in the first place.
 
  • #75
Yeah, I typically find flaws/typos in assignments first since I try to do them as soon as they are assigned. I'm assuming that everyone waited till this day or yesterday to start looking at the assignment.
 
  • #76
fader84 said:
I am also in this class and just recently started following the discussion, which is why I haven't contributed anything. In response to the earlier post about:
"I would also ask him if he expects people to already know how to do these kinds of proofs; or if you are expected to learn that set of skills in the course." (I don't really know how to do the quoting thing y'all were doing earlier so I just did it this way). I really have no idea how to do these proofs and would have had no idea where to start if EonsNearby hadn't asked the questions in the first place.

Just hit "Edit" on my post and it will show you all the markup I used. Or just hit "Quote" and it will quote the entire post for you.

Maybe you should all go see him at once. He needs to know that he's losing people from the getgo. Sometimes professors can forget all about what it's like to see this material for the first time.
EonsNearby said:
Yeah, I typically find flaws/typos in assignments first since I try to do them as soon as they are assigned. I'm assuming that everyone waited till this day or yesterday to start looking at the assignment.

You did well to jump on the assignment right away. This is a class where you want to stay ahead of the text, ahead of the lectures, and jump on the HW the moment you get it.
 
  • #77
Hopefully I did this right.
SteveL27 said:
Maybe you should all go see him at once. He needs to know that he's losing people from the getgo. Sometimes professors can forget all about what it's like to see this material for the first time.

Is a good idea but not sure how the professor would react. Possibly mentioning that multiple students that EonsNearby has talked to are having problems with the assignment would have about the same effect as multiple people coming to his office at once. If it doesn't, then the multiple people at once option can be explored.

SteveL27 said:
You did well to jump on the assignment right away. This is a class where you want to stay ahead of the text, ahead of the lectures, and jump on the HW the moment you get it.

I started looking at it when first assigned as well and tried to do the ones that I understood enough to at least get a partial answer for before I tried to do the ones that I didn't have a clue how to do. I'm a graduate student which means I have more of the problems to do, which is why it has taken me until now to look at this question. I am also rather bad at math which means it takes longer than normal for me to figure these things out.
 
  • #78
I started looking at it when first assigned as well and tried to do the ones that I understood enough to at least get a partial answer for before I tried to do the ones that I didn't have a clue how to do. I'm a graduate student which means I have more of the problems to do, which is why it has taken me until now to look at this question. I am also rather bad at math which means it takes longer than normal for me to figure these things out.

I wasn't trying to imply anything bad, like I think the other students are lazy or procrastinators or anything, when I said I assumed most people waited until recently to do this homework. I just thought that since hardly anyone responded, and when I did get a response, it was 2 days ago.
 
  • #79
I didn't think you were trying to imply anything. I withheld replying in the hopes that he would realize that there was a mistake and inform us like he did for question 1. I must have missed it when you ask about the other questions, to which my response would have been I just put down logic and hoped that he was satisfied with that. Well, logic and some of the definitions out of the book.
 
  • #80
I am also in this class, I figured out there was a error in the assignment, but I was not sure about it.
 
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  • #81
fader84 said:
I didn't think you were trying to imply anything. I withheld replying in the hopes that he would realize that there was a mistake and inform us like he did for question 1. I must have missed it when you ask about the other questions, to which my response would have been I just put down logic and hoped that he was satisfied with that. Well, logic and some of the definitions out of the book.
He realized the mistake after someone told him there is a mistake.
 

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