Comma
A typesetting symbol which has several distinct meanings in mathematics. It is used for a number of purposes.
1. To denote Boundaries between elements in a list, as in {1,2,3,...}.
2. To delimit indices in the element of a matrix, as in a_(i,j) (although it is frequently omitted when implied by context).
3. To indicate the comma derivative of a tensor.
4. In place of a decimal point in continental Europe, e.g., 3,14159.
See also
Comma Derivative, Decimal PointExplore with Wolfram|Alpha
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References
Bringhurst, R. The Elements of Typographic Style, 2nd ed. Point Roberts, WA: Hartley and Marks, p. 275, 1997.Referenced on Wolfram|Alpha
CommaCite this as:
Weisstein, Eric W. "Comma." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/Comma.html