Ultrametric

An ultrametric is a Metric which satisfies the following strengthened version of the Triangle Inequality,

Let be a Set, and let (where N is the Set of NaturalNumbers) denote the collection of sequences of elements of (i.e., all the possible sequences , ,, ...). For sequences , , let be the number of initial places where thesequences agree, i.e., , , ..., , but . Take if . Thendefining gives an ultrametric.

The p-adic Number metric is another example of an ultrametric.

• Dodecahedral Graph
• Dodecahedral Space
• Dodecahedron
• Dodecahedron 2-Compound
• Dodecahedron-Icosahedron Compound
• Dodecahedron Stellations
• Domain
• Domain Invariance Theorem
• Dome
• Dominance
• Domino
• Domino Problem
• Donaldson Invariants
• Donkin's Theorem
• Donut
• Doob's Theorem
• Dot
• Dot Product
• Variate
• Variation
• Variation Coefficient
• Variation of Argument
• Variation of Parameters
• Variety
• Varignon Parallelogram