The foundation of generalized parallel connections, 2-sums, and segment-cosegment exchanges of matroids

Abstract

We show that, under suitable hypotheses, the foundation of a generalized parallel connection of matroids is the relative tensor product of the foundations. Using this result, we show that the foundation of a 2-sum of matroids is the absolute tensor product of the foundations, and that the foundation of a matroid is invariant under segment-cosegment exchange.

35 pages. v2: Added more background information and made minor expository changes