The Structure of K-Cs: Transitive Cycle-free Partial Orders - Memoirs of the American Mathematical Society

Defines the class of cycle-free partial orders (CFPOs), and analyzes the CFPOs fulfilling a natural transitivity assumption, called $k$-connected set transitivity ($k$-$CS$-transitivity). This work generalizes Droste's classification of the countable $k$-transitive trees ($k \geq 2$).