Examples of ordered topology on R x R

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In summary, the ordered topology is defined by intervals and can be generated by half open and open intervals. The space {1} x (1, 2] has intervals of the form {x | (1, 1] < (1, x] < (1, 2]} and can also be defined with open intervals and a half open interval about {1, (1, 2]}. The space {1,2} x Z_+ contains the set {{1, 1} {1, 2} ... {2, 1}, {2, 2} ... } and has a basis of {x | (x - 1, x + 1), x in Z_+
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Pippi
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I am trying to understand the difference between ordered topology and subspace topology. For one, how do I write down ordered topology of the form {1} x (1, 2] ? How do I write down a basis for {1,2} x Z_+ ?
 
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  • #2
What order are you planning to put on these spaces?? (specifically the second one)
 
  • #3
I want to put dictionary order on them, so (1, 2) is less than (2, 2) and also less than (1,3). I don't know other orders can be put on them (maybe a metric?) than dictionary order.
 
  • #4
So, the order topology is by definition generated by intervals. That is

[tex]\{x~\vert~a<x<b\}[/tex]

Can you give a description of the intervals in your two spaces?
 
  • #5
For the space {1} x (1, 2], the intervals are half open intervals {x | (1, 1] < (1, x] < (1, 2]}. I can also define open intervals {x | (1, 1) < (1, x) < (1, 2)} and a half open interval about {1, (1, 2]}. Both are valid topology.

The space {1,2} x Z_+ contains the set {{1, 1} {1, 2} ... {2, 1}, {2, 2} ... }. Because I can define the basis {x | (x - 1, x + 1), x in Z_+} for space Z_+, the basis are {{1, (x - 1, x+1), {2, (x - 1, x +1)}}. The basis for x = 1 are {1, [1, 2)} and {2, [1, 2)}.

I can't find errors but this is suggesting that I can find many different order topology on a set? Infinitely many? :/.
 

1. What is an ordered topology?

An ordered topology is a mathematical concept that describes a particular way of ordering elements in a set. In this context, it refers to the way that the real numbers on the x-axis and y-axis of a Cartesian plane are ordered and how this affects the topology of the space.

2. What is the topology of R x R?

The topology of R x R, also known as the product topology, is a topology on the Cartesian product of two topological spaces. In this case, R x R refers to the Cartesian plane, and the topology is defined by open sets that are the unions of intervals along the x-axis and y-axis.

3. How is the topology of R x R different from the usual topology on R?

The usual topology on R is defined by open intervals, while the topology of R x R is defined by open sets that are unions of intervals along both the x-axis and y-axis. This means that in the product topology, open sets can be more complex and contain sets that are not intervals, such as the union of two intersecting intervals.

4. What are some examples of open sets in the ordered topology on R x R?

Some examples of open sets in the ordered topology on R x R include:

  • The union of two horizontal intervals, such as (-2, 3) ∪ (5, 7), which forms a rectangle on the Cartesian plane.
  • The union of a horizontal interval and a vertical interval, such as (-2, 3) ∪ (4, 6), which forms a right-angled triangle on the Cartesian plane.
  • The union of two intersecting intervals, such as (-2, 3) ∪ (2, 5), which forms a shape similar to the letter "X" on the Cartesian plane.

5. How does the ordered topology on R x R relate to the concept of ordered pairs?

The ordered topology on R x R is closely related to the concept of ordered pairs, as it is defined by the ordering of elements on the x-axis and y-axis in a Cartesian plane. In this topology, the order of the elements in a pair matters, as it will determine the position of the point on the Cartesian plane and which open sets it belongs to. This is different from other topologies where the order of elements in a pair may not matter, such as in the discrete topology.

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