diff --git a/spaces/S000030/README.md b/spaces/S000030/README.md index bfcfa59f28..d818ce8327 100644 --- a/spaces/S000030/README.md +++ b/spaces/S000030/README.md @@ -1,9 +1,10 @@ --- uid: S000030 -name: Hilbert space +name: Hilbert space $\ell^2$ aliases: - - $\ell^2$ - - Fréchet space + - Fréchet space $\mathbb R^\omega$ + - Continuous real-valued functions on the unit interval + - $C([0,1])$ counterexamples_id: 36 refs: - doi: 10.1007/978-1-4612-6290-9 @@ -17,5 +18,12 @@ Let $X$ be the space $\ell^2$ of all sequences $x = \langle x_i \rangle$ of real This space is homeomorphic to $\mathbb{R}^\omega$ with the product topology (Fréchet space). For this deep result due to R. D. Anderson, see for example {{doi:10.1090/S0002-9904-1968-12044-0}}. -Defined as counterexamples #36 ("Hilbert Space") and #37 ("Fréchet Space") -in {{doi:10.1007/978-1-4612-6290-9}}. +More generally, any infinite-dimensional separable Banach space or separable Fréchet space is homeomorphic to $\mathbb R^\omega$. See {{wikipedia:Anderson–Kadec theorem}}. + +In particular, the following are all homeomorphic as topological spaces: +- $\mathbb R^\omega$ +- Sequence spaces $\ell^p$ ($1 \leq p < + \infty$) +- Spaces $L^p([0,1])$ ($1 \leq p < + \infty$) of Lebesgue measurable functions with finite $L^p$-norm +- the Banach space $C([0,1])$ of real-valued continuous functions on $[0,1]$ with the supremum norm + +Specific instances of the above are counterexamples #36 ("Hilbert Space"), #37 ("Fréchet Space"), and #108 ("$C[0,1]$") in {{doi:10.1007/978-1-4612-6290-9}}. diff --git a/spaces/S000106/README.md b/spaces/S000106/README.md deleted file mode 100644 index 869a768661..0000000000 --- a/spaces/S000106/README.md +++ /dev/null @@ -1,15 +0,0 @@ ---- -uid: S000106 -name: Continuous real-valued functions on the unit interval -aliases: - - C(I) - - C[0,1] -counterexamples_id: 108 -refs: - - doi: 10.1007/978-1-4612-6290-9 - name: Counterexamples in Topology ---- -The space of continuous real-valued functions \(C(I)\) or \(C(I,\mathbb R)\). Its topology is generated by the sup norm \(d(f,g) = \sup|f(t) - g(t)|\). - -Defined as counterexample #108 ("\(C[0,1]\)") -in {{doi:10.1007/978-1-4612-6290-9}}. diff --git a/spaces/S000106/properties/P000017.md b/spaces/S000106/properties/P000017.md deleted file mode 100644 index 27f8c62103..0000000000 --- a/spaces/S000106/properties/P000017.md +++ /dev/null @@ -1,10 +0,0 @@ ---- -space: S000106 -property: P000017 -value: false -refs: -- doi: 10.1007/978-1-4612-6290-9_6 - name: Counterexamples in Topology ---- - -See item #3 for space #108 in {{doi:10.1007/978-1-4612-6290-9_6}}. diff --git a/spaces/S000106/properties/P000023.md b/spaces/S000106/properties/P000023.md deleted file mode 100644 index a117665dfc..0000000000 --- a/spaces/S000106/properties/P000023.md +++ /dev/null @@ -1,10 +0,0 @@ ---- -space: S000106 -property: P000023 -value: false -refs: -- doi: 10.1007/978-1-4612-6290-9_6 - name: Counterexamples in Topology ---- - -See item #3 for space #108 in {{doi:10.1007/978-1-4612-6290-9_6}}. diff --git a/spaces/S000106/properties/P000026.md b/spaces/S000106/properties/P000026.md deleted file mode 100644 index f7ba7186ea..0000000000 --- a/spaces/S000106/properties/P000026.md +++ /dev/null @@ -1,10 +0,0 @@ ---- -space: S000106 -property: P000026 -value: true -refs: -- doi: 10.1007/978-1-4612-6290-9_6 - name: Counterexamples in Topology ---- - -See item #2 for space #108 in {{doi:10.1007/978-1-4612-6290-9_6}}. diff --git a/spaces/S000106/properties/P000038.md b/spaces/S000106/properties/P000038.md deleted file mode 100644 index 8c92c75e18..0000000000 --- a/spaces/S000106/properties/P000038.md +++ /dev/null @@ -1,10 +0,0 @@ ---- -space: S000106 -property: P000038 -value: true -refs: -- doi: 10.1007/978-1-4612-6290-9_6 - name: Counterexamples in Topology ---- - -See item #4 for space #108 in {{doi:10.1007/978-1-4612-6290-9_6}}. diff --git a/spaces/S000106/properties/P000043.md b/spaces/S000106/properties/P000043.md deleted file mode 100644 index e56b9a2c7d..0000000000 --- a/spaces/S000106/properties/P000043.md +++ /dev/null @@ -1,10 +0,0 @@ ---- -space: S000106 -property: P000043 -value: true -refs: -- doi: 10.1007/978-1-4612-6290-9_6 - name: Counterexamples in Topology ---- - -See item #4 for space #108 in {{doi:10.1007/978-1-4612-6290-9_6}}. diff --git a/spaces/S000106/properties/P000053.md b/spaces/S000106/properties/P000053.md deleted file mode 100644 index 3c78880355..0000000000 --- a/spaces/S000106/properties/P000053.md +++ /dev/null @@ -1,13 +0,0 @@ ---- -space: S000106 -property: P000053 -value: true -refs: -- doi: 10.1007/978-1-4612-6290-9_6 - name: Counterexamples in Topology ---- - -The topology is defined by the sup norm $d(f,g)=sup|f(t)−g(t)|$. - -Asserted in the General Reference Chart for space #108 in -{{doi:10.1007/978-1-4612-6290-9_6}}. diff --git a/spaces/S000106/properties/P000055.md b/spaces/S000106/properties/P000055.md deleted file mode 100644 index d98ae65203..0000000000 --- a/spaces/S000106/properties/P000055.md +++ /dev/null @@ -1,11 +0,0 @@ ---- -space: S000106 -property: P000055 -value: true -refs: -- doi: 10.1007/978-1-4612-6290-9_6 - name: Counterexamples in Topology ---- - -Asserted in the General Reference Chart for space #108 in -{{doi:10.1007/978-1-4612-6290-9_6}}. diff --git a/spaces/S000106/properties/P000087.md b/spaces/S000106/properties/P000087.md deleted file mode 100644 index 50b1ac23eb..0000000000 --- a/spaces/S000106/properties/P000087.md +++ /dev/null @@ -1,10 +0,0 @@ ---- -space: S000106 -property: P000087 -value: true -refs: -- doi: 10.1007/978-1-4612-6290-9_6 - name: Counterexamples in Topology ---- - -The space is a normed linear space. In particular, it is a topological group with addition. diff --git a/spaces/S000106/properties/P000129.md b/spaces/S000106/properties/P000129.md deleted file mode 100644 index ade61becd9..0000000000 --- a/spaces/S000106/properties/P000129.md +++ /dev/null @@ -1,7 +0,0 @@ ---- -space: S000106 -property: P000129 -value: false ---- - -The space is non-trivial by definition.