The definition of the exchange lemma












2












$begingroup$


a



We've just learnt about the exchange lemma, and I was looking at someone else's notes - I don't understand the point 2. How can $psi_t in {psi_1,...,psi_n }$? Should it not be in ${varphi_1,...,varphi_n}$?










share|cite|improve this question











$endgroup$








  • 1




    $begingroup$
    Yes, you're right. That's most probably a typo. What book is that? +1
    $endgroup$
    – DonAntonio
    Jan 16 '14 at 18:50












  • $begingroup$
    It's not a book, just some notes I found online - sorry for asking such a basic question, just wanted to make sure I wasn't missing anything important. Thanks.
    $endgroup$
    – Warz
    Jan 16 '14 at 18:51






  • 1




    $begingroup$
    Ok, fine. My advice is that you continue the search: the above is not, imo, the best way to present the very important exchange Theorem, typo aside.
    $endgroup$
    – DonAntonio
    Jan 16 '14 at 18:52










  • $begingroup$
    Any recommendations? I'm looking at the proof, and I can barely follow it, perhaps I just don't understand the exchange lemma.
    $endgroup$
    – Warz
    Jan 16 '14 at 18:53










  • $begingroup$
    Try even Wikipedia, @Warz, or books.google.co.il/… , or pancratz.org/notes/LinearAlgebra.pdf , theorem 1.5 , etc.
    $endgroup$
    – DonAntonio
    Jan 16 '14 at 19:00
















2












$begingroup$


a



We've just learnt about the exchange lemma, and I was looking at someone else's notes - I don't understand the point 2. How can $psi_t in {psi_1,...,psi_n }$? Should it not be in ${varphi_1,...,varphi_n}$?










share|cite|improve this question











$endgroup$








  • 1




    $begingroup$
    Yes, you're right. That's most probably a typo. What book is that? +1
    $endgroup$
    – DonAntonio
    Jan 16 '14 at 18:50












  • $begingroup$
    It's not a book, just some notes I found online - sorry for asking such a basic question, just wanted to make sure I wasn't missing anything important. Thanks.
    $endgroup$
    – Warz
    Jan 16 '14 at 18:51






  • 1




    $begingroup$
    Ok, fine. My advice is that you continue the search: the above is not, imo, the best way to present the very important exchange Theorem, typo aside.
    $endgroup$
    – DonAntonio
    Jan 16 '14 at 18:52










  • $begingroup$
    Any recommendations? I'm looking at the proof, and I can barely follow it, perhaps I just don't understand the exchange lemma.
    $endgroup$
    – Warz
    Jan 16 '14 at 18:53










  • $begingroup$
    Try even Wikipedia, @Warz, or books.google.co.il/… , or pancratz.org/notes/LinearAlgebra.pdf , theorem 1.5 , etc.
    $endgroup$
    – DonAntonio
    Jan 16 '14 at 19:00














2












2








2





$begingroup$


a



We've just learnt about the exchange lemma, and I was looking at someone else's notes - I don't understand the point 2. How can $psi_t in {psi_1,...,psi_n }$? Should it not be in ${varphi_1,...,varphi_n}$?










share|cite|improve this question











$endgroup$




a



We've just learnt about the exchange lemma, and I was looking at someone else's notes - I don't understand the point 2. How can $psi_t in {psi_1,...,psi_n }$? Should it not be in ${varphi_1,...,varphi_n}$?







linear-algebra vector-spaces






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Dec 24 '18 at 7:24









Glorfindel

3,41381830




3,41381830










asked Jan 16 '14 at 18:47









WarzWarz

4641416




4641416








  • 1




    $begingroup$
    Yes, you're right. That's most probably a typo. What book is that? +1
    $endgroup$
    – DonAntonio
    Jan 16 '14 at 18:50












  • $begingroup$
    It's not a book, just some notes I found online - sorry for asking such a basic question, just wanted to make sure I wasn't missing anything important. Thanks.
    $endgroup$
    – Warz
    Jan 16 '14 at 18:51






  • 1




    $begingroup$
    Ok, fine. My advice is that you continue the search: the above is not, imo, the best way to present the very important exchange Theorem, typo aside.
    $endgroup$
    – DonAntonio
    Jan 16 '14 at 18:52










  • $begingroup$
    Any recommendations? I'm looking at the proof, and I can barely follow it, perhaps I just don't understand the exchange lemma.
    $endgroup$
    – Warz
    Jan 16 '14 at 18:53










  • $begingroup$
    Try even Wikipedia, @Warz, or books.google.co.il/… , or pancratz.org/notes/LinearAlgebra.pdf , theorem 1.5 , etc.
    $endgroup$
    – DonAntonio
    Jan 16 '14 at 19:00














  • 1




    $begingroup$
    Yes, you're right. That's most probably a typo. What book is that? +1
    $endgroup$
    – DonAntonio
    Jan 16 '14 at 18:50












  • $begingroup$
    It's not a book, just some notes I found online - sorry for asking such a basic question, just wanted to make sure I wasn't missing anything important. Thanks.
    $endgroup$
    – Warz
    Jan 16 '14 at 18:51






  • 1




    $begingroup$
    Ok, fine. My advice is that you continue the search: the above is not, imo, the best way to present the very important exchange Theorem, typo aside.
    $endgroup$
    – DonAntonio
    Jan 16 '14 at 18:52










  • $begingroup$
    Any recommendations? I'm looking at the proof, and I can barely follow it, perhaps I just don't understand the exchange lemma.
    $endgroup$
    – Warz
    Jan 16 '14 at 18:53










  • $begingroup$
    Try even Wikipedia, @Warz, or books.google.co.il/… , or pancratz.org/notes/LinearAlgebra.pdf , theorem 1.5 , etc.
    $endgroup$
    – DonAntonio
    Jan 16 '14 at 19:00








1




1




$begingroup$
Yes, you're right. That's most probably a typo. What book is that? +1
$endgroup$
– DonAntonio
Jan 16 '14 at 18:50






$begingroup$
Yes, you're right. That's most probably a typo. What book is that? +1
$endgroup$
– DonAntonio
Jan 16 '14 at 18:50














$begingroup$
It's not a book, just some notes I found online - sorry for asking such a basic question, just wanted to make sure I wasn't missing anything important. Thanks.
$endgroup$
– Warz
Jan 16 '14 at 18:51




$begingroup$
It's not a book, just some notes I found online - sorry for asking such a basic question, just wanted to make sure I wasn't missing anything important. Thanks.
$endgroup$
– Warz
Jan 16 '14 at 18:51




1




1




$begingroup$
Ok, fine. My advice is that you continue the search: the above is not, imo, the best way to present the very important exchange Theorem, typo aside.
$endgroup$
– DonAntonio
Jan 16 '14 at 18:52




$begingroup$
Ok, fine. My advice is that you continue the search: the above is not, imo, the best way to present the very important exchange Theorem, typo aside.
$endgroup$
– DonAntonio
Jan 16 '14 at 18:52












$begingroup$
Any recommendations? I'm looking at the proof, and I can barely follow it, perhaps I just don't understand the exchange lemma.
$endgroup$
– Warz
Jan 16 '14 at 18:53




$begingroup$
Any recommendations? I'm looking at the proof, and I can barely follow it, perhaps I just don't understand the exchange lemma.
$endgroup$
– Warz
Jan 16 '14 at 18:53












$begingroup$
Try even Wikipedia, @Warz, or books.google.co.il/… , or pancratz.org/notes/LinearAlgebra.pdf , theorem 1.5 , etc.
$endgroup$
– DonAntonio
Jan 16 '14 at 19:00




$begingroup$
Try even Wikipedia, @Warz, or books.google.co.il/… , or pancratz.org/notes/LinearAlgebra.pdf , theorem 1.5 , etc.
$endgroup$
– DonAntonio
Jan 16 '14 at 19:00










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