topology/chu+~ no^m

[Ha Le <ha@math.wayne.edu>]

Dear VietHai Nguyen,
I'm sorry for not replying sooner. I'm a fraid I can not visualize your 
example of "two adjacent surfaces". However, don't you think that in your 
formula for IN(A U B), IN(A \intersect B) is redundant? I mean, it's easy 
to show that if X \in Y, then IN(X) \in IN(Y), so IN(A \interersect B) is 
already in both IN(A) and IN(B).
Anyway, this stuff has become too technical and i'm not sure whether other 
forummers (except, probably the great engineer Blue Wolverine!) like to 
read about this. So send me private email next time if you still want to 
talk about this kind of abstract nonsense!
cheers!
ha@math.wayne.edu
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To anh TMTie^'n, A'i Vie^.t, H'La^m...

Ca?m o+n ca'c anh dda~ ta^.n ti`nh gia?ng gia?i ve^` chu+~ no^m, to^i 
cu~ng co' ddo.c qua o+? dda^u ddo' no'i la` chu+~ no^m xua^'t hie^.n va`o 
khoa?ng the^' ky? thu+' 9-10, nhu+ng cha?ng tha^'y no'i xua^'t hie^.n 
tu+` dda^u ra! To^i xin ddu+o+.c ho?i the^m ve^` vie^.c "pha^n pho^'i" 
su+? du.ng chu+~ Ha'n va` chu+~ No^m nga`y xu+a? Vi' du. khi ddi thi thi` 
ca'c cu. du`ng "ngo.ai ngu+~" hay "quo^'c ngu+~" ? Nha^n tie^.n to^i 
pha?i no'i ngay dde^? ca'c Ba'c co`n "ddi.nh hu+o+'ng nghie^n cu+'u": 
Chu~ "O^ng Ha`" tre^n ca'i chuo^ng o+? ba~i bie^?n DDo^` So+n cha?ng co' 
di'nh da'ng gi` dde^'n Ha` Le^ na`y ca?, tu+` be' dde^'n gio+` to^i 
chu+a ddi ta('m bie^?n DDO^` So+n la^`n na`o. Nhu+ng xem ra nga`nh kha?o 
co^? ho.c "du+o+'i nu+o+'c" cu?a VN ta va^~n co`n o^'i vie^.c dde^? la`m...

Thien Quang Ha Le.