Every separable Banach space is a quotient of $\ell_1$
97621
Every separable Banach space is isomorphic to $\ell_1/A$ for some closed $A\subset \ell_1$
126744
Is any Banach space a dual space?
151046
Closure of the invertible operators on a Banach space
74877
Every metric space with a countable base is separable
92497
Isometric Embedding of a separable Banach Space into $\ell^{\infty}$
71682
Proving that $X$ is a Banach space iff convergence of $\sum\|x_n\|$ implies convergence of $\sum x_n$
50160
The quotient norm on $\ell^{\infty}(\mathbb{N}) / c_0 (\mathbb{N})$ is given by $\limsup_{n \in \mathbb{N}} |x_n|$.
22295
Subspace of a separable space is separable
16512
Product of $T_1$ spaces is $T_1$
144112
Show that $c_0$ is a Banach space with the norm $\rVert \cdot \lVert_\infty$
95074
Separability of $l^{p}$ spaces
51177
When are two norms equivalent on a Banach space?
125277
Image of the tensor product of strict maps of Banach spaces
63285
Prove that this space is not Banach
69528
Metrizability of quotient spaces of metric spaces
157499
Every finite extension of a finite field is separable
53883
If every absolutely convergent series is convergent then $X$ is Banach