Let $X$ be a Banach space, and $E$ a closed subspace, then $X/E$ is a Banach space
95887
How to show that quotient space $X/Y$ is complete when $X$ is Banach space, and $Y$ is a closed subspace of $X$?
22295
Subspace of a separable space is separable
97621
Every separable Banach space is isomorphic to $\ell_1/A$ for some closed $A\subset \ell_1$
115219
If $E$ is Lebesgue measurable, show that there exists a closed set $F$ with $F \subset E$ and $m(E\setminus F)<\epsilon$
12212
Showing a certain subspace of Hilbert space is dense
53883
If every absolutely convergent series is convergent then $X$ is Banach
139272
On the norm of a quotient of a Banach space.
109046
Is the complement of an open ball in a Banach space connected?
73462
Nested sequences of balls in a Banach space
124458
Quotient of a Banach space $X$ gets quotient topology under standard norm induced from $X$.
134492
Proving that a Hölder space is a Banach space
87655
Consequence of the Hahn-Banach Theorem
41611
Open and closed set in n by n matrices space.
96717
Hahn-Banach Theorem for separable spaces without Zorn's Lemma
79024
the derivation of E(X|X)
154762
Dual space of a finite dimensional normed space
15839
equivalent norms in Banach spaces of infinite dimension