  The following question was raised by Tuza in 1990 and Erdos et al. in 1992:
if every edge of an n-vertex chordal graph G is contained in a clique of size
at least four, does G have a clique transversal, i.e., a set of vertices
meeting all non-trivial maximal cliques, of size at most n/4? We prove that
every such graph G has a clique transversal of size at most 2(n-1)/7 if n>=5,
which is the best possible bound.
