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The outside of universe is a higher dimension which contains lots of universe?
Hi , welcome aboard!
Logic book? there is this kinda stuff? thanks
Give u a tip .
R , r are the radius of two circles , scribing the triangle. one is outside , one is inside , I dont know what those are called in English.
Thanks , I am studying the proof , I used to do maths like Geometry , Calculus . I havent really gotten used to Abstract maths.
Maybe
Can I use induction , assuming S can be the intersection of n open sets , then consider n+1 ?
Oh , I think I have a better idea , since every open sets can be a intersection of a collection of countable open set. right?
Prove that every closed set in R^1 is the intersection of a countable collection of open sets.
I know that
but I don't exactly know how to do it.
Yeah , it's pretty big ,
you can make it
I turned it into the number divided by has 3,4,5 remainder 1 .
Wow , it's strange , that I got 420k-161 by extended Euclidean algorithm for Chinese remainder theorem.
I think it's infinite.
the first number is 2 ? I think it has many answers ..
A is dense in X if for any point x in X, any neighborhood of x contains at least one point from A.
Then the set of Rational and the set of irrational are dense in R^1 ,right? So any neighborhood of x in R^1 contain both rational and irrational .
But how to prove that the set of Rational and the set of irrational are dense in R^1 ?
but I haven't learned about that , not yet . Then how should I solve that problem? Is finding an algorithm a correct way to do it?
If I am trying to prove than something exist in something , Can I design an algorithm to prove?
I got a very clumsy proof , feel free to correct me , but don't go too hard on me , XD
Santa = Satan
This one , I dont think just a coincidence...lol
why did that hyena laugh?
Here is the question
Show that if G is a finite group of even order , then G has an odd number of elements of order 2. Note that e is the only element of order 1.
If I regard G as
Is it true that
Yea , I got it . b=a^-1 (ab) , when couldnt I think of that.