Perfect Triangle Families
نویسنده
چکیده
The Dual Theorem of Lucchesi and Younger [3] states that in every (finite) planar directed graph, there is a minimum feedback set (an edge set containing at least one edge of each directed circuit) whose cardinality is equal to the maximum number of mutually edge-disjoint directed circuits. In this note we prove that an analogue of this classical result remains valid when 3-circuits (that is, triangles with cyclic orientation) are considered instead of the family of all circuits.
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