ファイル:Real projective line.svgDescriptionReal projective line.svg English: Illustration of real projective line Date 16 September 2008, 06:34 (UTC) Source Own work Author Oleg Alexandrov
ファイル:Real Projective Line (RP1).pnglicense: English The real projective line can be modeled by the [[projectively extended real line]], which consists of the [[real line]] together with a