Hausdorff Axioms

Describe subsets of elements in a Neighborhood Set of . The Neighborhood is assumed tosatisfy:

1. There corresponds to each point at least one Neighborhood , and each Neighborhood contains the point .

2. If and are two Neighborhoods of the same point , there must exist aNeighborhood that is a subset of both.

3. If the point lies in , there must exist a Neighborhood that is a Subset of.

4. For two different points and , there are two corresponding Neighborhoods and with no points in common.

• Analogy
• Analysis
• Analysis Situs
• Analytic Continuation
• Analytic Function
• Analytic Geometry
• Analytic Set
• Anarboricity
• Anchor
• Anchor Ring
• And
• Anderson-Darling Statistic
• Andrews Cube
• Nilpotent Lie Group
• Nilpotent Matrix
• Nim
• Nim-Heap
• Nim-Sum
• Nim-Value
• n-in-a-Row
• Nine-Point Center
• Nine-Point Circle
• Nine-Point Conic
• Nint
• Nint Zeta Function