Topology
From Vectorcalcumb
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- | + | =Topology= | |
- | + | ==What is a topology on a set?== | |
- | + | ;Open sets. :Sets which do not contain their boundary, that is if | |
- | + | <m>A \\subset \\Re^n</m> A is open if <m> A = int(a)</m> | |
- | + | **Closed sets. | |
- | + | **Neighborhood of a point. | |
- | < | + | **Interior points of a set. Interior of a set. |
- | + | **Exterior point of a set. Exterior of a set. | |
- | + | **Boundary point of a set. Boundary of a set. | |
- | + | **Compact sets. | |
- | + | **Acumulation point of a set. | |
- | + | ==The "ball" topology on R<sup>n</sup>== | |
- | + | **The norm-2 on R<sup>n</sup>. | |
- | + | **Open balls in norm-2. | |
- | + | **Open sets in the norm-2 topology. | |
- | + | ==The "box" topology on R<sup>n</sup>== | |
- | + | **The norm-infinity on R<sup>n</sup>. | |
- | + | **Open balls in norm-infinity. | |
- | + | **Open sets in the norm-infinity topology. | |
- | + | *Fact: The "ball" topology on R<sup>n</sup> is the same as the "box" topology on R<sup>n</sup> | |
- | + | *Induced topology on a subset of R<sup>n</sup> | |
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Revision as of 05:08, 8 February 2006
Contents |
Topology
What is a topology on a set?
- Open sets.
- Sets which do not contain their boundary, that is if
<m>A \\subset \\Re^n</m> A is open if <m> A = int(a)</m>
- Closed sets.
- Neighborhood of a point.
- Interior points of a set. Interior of a set.
- Exterior point of a set. Exterior of a set.
- Boundary point of a set. Boundary of a set.
- Compact sets.
- Acumulation point of a set.
The "ball" topology on Rn
- The norm-2 on Rn.
- Open balls in norm-2.
- Open sets in the norm-2 topology.
The "box" topology on Rn
- The norm-infinity on Rn.
- Open balls in norm-infinity.
- Open sets in the norm-infinity topology.
- Fact: The "ball" topology on Rn is the same as the "box" topology on Rn
- Induced topology on a subset of Rn