An exact result for 3-graphs

  title={An exact result for 3-graphs},
  author={Peter Frankl and Zolt{\'a}n F{\"u}redi},
  journal={Discret. Math.},
Abstract The aim of this paper is to prove Theorem 1 which gives a full description of families of 3-subsets in which any 4 points contain 0 or 2 members of the family. 

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