#Chapters
Introduction. Words, ordered set partitions, and symmetric cycle exchange.
Operations and minors. Loops and coloops, restrictions, deletion and contraction, and direct sums.
Ultra-log-concavity. Rigid width-three posets and three-color matroid encodings.
Rank. Ordinary color projections, joint cell counts, rank data, and the boundary of current rank descriptions.
Assignment polytopes. Assignment-vector geometry, edge directions, inequality descriptions, and the principal open questions.