$C(K)$ is reflexive if and only if $K$ is finite
115120
Finite dimensional $C^*$-algebras
95244
Prove that a finite union of closed sets is also closed
125073
Finite-dimensional subspaces of normed vector spaces are direct summands
1251
If $[G:K]$ is finite, then $[H:H \cap K] = [G:K]$ iff $G = HK$ (Hungerford Proposition 4.8, Proof)
108734
$T$ is continuous if and only if $\ker T$ is closed
89058
Question on finite Vector Spaces, injective, surjective and if $V$ is not finite
144225
$\ell_p$ is Hilbert if and only if $p=2$
45792
Rigorous proof that surjectivity implies injectivity for finite sets
19773
Is finite additivity a property of the Lebesegue outer measure?
157202
$A\oplus C \cong B \oplus C$. Is $A \cong B$ when $C$ is finite, A and B infinite.
93111
Finiteness of the Algebraic Closure
147013
Subset of a finite set is finite
74015
Number of relations that are both symmetric and reflexive
157081
The cartesian product of a finite amount of countable sets is countable.
103769
The Cartesian product of a finite number of countable sets is countable
81471
Finite dimensional spaces
78256
Finite additivity in outer measure