On the Number of Circuit-cocircuit Reversal Classes of an Oriented Matroid
نویسنده
چکیده
Gioan introduced the circuit-cocircuit reversal system of an oriented matroid and showed that its cardinality equals the number of bases when the underlying matroid is regular. We prove that the equality fails whenever the underlying matroid is not regular, hence giving a new characterization of regular matroids.
منابع مشابه
Intersections of circuits and cocircuits in binary matroids
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