cross-ratio
See also: crossratio
English
Alternative forms
- crossratio
Etymology
cross- + ratio
Noun
cross-ratio (plural cross-ratios)
- (geometry) A special number associated with an ordered quadruple of collinear points, particularly points on a projective line, and preserved by the fractional linear transformations.
Synonyms
- anharmonic ratio
- double ratio
Translations
a special number associated with an ordered quadruple of collinear points, particularly points on a projective line, and preserved by the fractional linear transformations
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