∩ M j = 0̸ for all i ≠ j and ⋃ i M i = V . In this note we are interested in the maximum
number of edges of a hypergraph H with a unique perfect matching. Hetyei observed (see,
eg, [1], [2], [3]) that for ordinary graphs (ie k = 2 ), this number cannot exceed m 2 . To see
this, note that at most two …