Approval Ballot Triangles and Strict-Sense Ballots

Published in Enumerative Combinatorics and Applications, 2026

A. Beveridge, I. Calaway, Approval Ballot Triangles and Strict-Sense Ballots, Enumerative Combinatorics and Applications, 6:3 (2026) Article S2R21

Preprint link: https://ecajournal.haifa.ac.il/Volume2026/ECA2026_S2A21.pdf

We consider a family of binary triangular arrays, called approval ballot triangles (ABTs), that are in bijection with totally symmetric self-complementary plane partitions (TSSCPPs). These triangles correspond to a ballot process in which voters select their collection of approved candidates rather than voting for a single person. We situate ABTs within the ballot problem literature and then show that a strict-sense ballot can be decomposed into a list of sequentially compatible ABTs.