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seen Dec 23 at 5:04

Jun
15
comment Differences between reflexives and projectives modules
@Francisco Pedromo You can look up Enochs' page at the University of Kentucky website, math.as.uky.edu. I believe he has a CV and list of publications there.
Jun
15
comment Differences between reflexives and projectives modules
@Francisco Pedromo I believe Enochs has done a fair amount of work with reflexive modules. If you have access to MathSciNet you could check out his publications. You might find something of interest.
Feb
13
awarded  Yearling
Jan
12
revised About injective hull
now typed in TeX.
Aug
17
awarded  Editor
Aug
17
revised Why are noetherian rings such natural objects in algebraic geometry?
edited body
Aug
16
answered Why are noetherian rings such natural objects in algebraic geometry?
Jul
1
answered Textbook recommendations for undergraduate proof-writing class
May
30
comment What has happened to Lang's Files and other political texts?
@Emerton - Maybe. I had a friend who was writing a thesis with Lang and got fed up with either Lang or his thesis, and told Lang off with some very choice words. Half the department was outraged, the other half cheered. Lang was not universally loved, I guess. Might have influenced Yale's decision.
May
30
comment Old books still used
@Andreas - I have the English translation of the seventh edition with me. It has a condensed treatment of elimination. I use this book often as a reference, and have a couple of earlier editions. I especially like the section on factorization in a finite number of steps in the second edition, which is missing from later ones. van der Waerden presents a proof due to Kronecker for the case of polynomials with rational coefficients. From what he says in the preface to the second edition, I believe this is a concession to intuitionism.
Aug
22
comment Is primary decomposition still important?
Very nicely done. I tried to give more than plus one, but the site is too smart. I would've given several more if I could.
Mar
1
awarded  Necromancer
Feb
29
answered Do you find your students are less competent in basic algebra and arithmetic, and, if so, do you believe that this is due to overuse of calculators at an early level?
Feb
29
awarded  Commentator
Feb
29
comment Do names given to math concepts have a role in common mistakes by students?
Or my favorite from Lang's "Algebra": "a ring $R$ is said to be simple if it is semi-simple and ... ."
Feb
10
comment minimal divisible group
Your $E$ is what would be called the divisible hull (or envelope) of $A$. Essentially by definition, $E$ is essential over $A$. This is the result of several equivalent conditions that are summarized in Section 4.2 of Lambek's "Lectures on Rings and Modules." For abelian groups, or modules over a PID, injective is equivalent to divisible.
Jan
3
comment Books you would like to see translated into English.
I don't know how easy the French is in EGA or SGA, but the French in Grothendieck's "Sur quelques points d'algebre homologique", the Tohoku paper, is terribly opaque. I read French well, but that paper was an exceptional challenge. I would welcome an English translation.
Jan
2
answered Depressed graduate student.
Jan
1
comment Demonstrating that rigour is important
If one wants to carry this to the extreme, any divergent series with the property that the n-th term goes to zero will converge on a calculator as the terms will eventually fall below the underflow value for the calculator, and hence be considered to be zero.
Nov
9
comment Using slides in math classroom
In lower level math courses at a US university, most students do not want to be in the course to begin with. Providing slides, or even lecture notes, on-line would make it very tempting for them not to come to class. This is a consequence that must be weighed in any decision to use slides. If a student is physically present, you still have an opportunity to reach them.