EnglishEnglishAdd translationThis article is a stubStub. This concept is still a minimal draft.Every subgroup of (R,+)(\R,+)(R,+) is either dense in R\RR, or cyclic of the form aZa\ZaZ for some a≥0a\geq 0a≥0. Problems using this concept (0)No listed problems link to this concept yet.Problems using this concept (spoiler) (0)No listed problems use this concept as a spoiler yet.