Thursday, January 31, 2008

Finally a serious student

4 comments:

Tecumseh said...

Speaking of which, here's a horrible notation conflict I got enmeshed in my class yesterday: how do you write the preimage of a set under the inverse of a [bijective] function? (f^{-1})^{-1}(X)?

Mr roT said...

What's the problem if it's a bij? Am I being an idiot?

Tecumseh said...

No real problem, it's only that f^{-1} has two distinct meanings -- not to mention that many students mistake it for 1/f.

Mr roT said...

What two distince meanings (barring 1/f)? There's the full preimage but for an inj that's just a point... I am still too slow for you, AI. Please don't take back the recommendation letters you wrote...