{
  "id": "math/0411076",
  "version": "v1",
  "published": "2004-11-03T22:13:56.000Z",
  "updated": "2004-11-03T22:13:56.000Z",
  "title": "A simple proof of a theorem of Karrass and Solitar",
  "authors": [
    "Delaram Kahrobaei"
  ],
  "comment": "2 pages. to appear",
  "categories": [
    "math.GR"
  ],
  "abstract": "In this note we give a particularly short and simple proof of the following theorem of Karrass and Solitar. Let $H$ be a finitely generated subgroup of a free group $F$ with infinite index $[F:H]$. Then there is a nontrivial normal subgroup $N$ of $F$ such that $N\\cap H = \\{1\\}$.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2004-11-03T22:13:56.000Z"
    }
  ],
  "analyses": {
    "subjects": [
      "20E05"
    ],
    "keywords": [
      "simple proof",
      "nontrivial normal subgroup",
      "infinite index",
      "free group",
      "finitely generated subgroup"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 2,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2004math.....11076K"
    }
  }
}