# Thread: Disjoint union of manifolds

1. ## Disjoint union of manifolds

Hey, before I write this up I just am curious if anyone knows if the following is correct.

Theorem: Let $\left\{\mathfrak{M}_n\right\}_{n\in\mathbb{N}}$ be a class of $m$-manifolds. Then, $\mathfrak{M}=\coprod_{n=1}^{\infty}\mathfrak{M}_n$ is an $m$-manifold under the coproduct topology.

Right?

2. If you don't know whether it is correct or not, then don't call it a theorem

3. Originally Posted by Moo
If you don't know whether it is correct or not, then don't call it a theorem
If you don't know the answer, then don't respond to the thread!

4. You're one to talk May I mention a thread in advanced probability & statistics ? Plus all the other times when you said "I'll go back later with the solution" and never came back, while it would have been better not to answer ? Hey so I don't see the problem with my reply