generated from smyalygames/quartz
6 lines
322 B
Markdown
6 lines
322 B
Markdown
# Definition
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A [[Metric]] on a set $X$ is a function $d : X \times X \to [ \, 0, \infty \rangle$ such that
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1. $d(x,y) = d(y, x), \; \forall x,y \in X$
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2. $d(x, y) = 0 \iff x = y$
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3. $d(x,z) \leq d(x,y) + d(y, z)$ (think of this as a triangle and Pythagoras' Theorem)
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Think of $d(x, y)$ as the distance between $x$ and $y$. |