Finite Marchal growth chains

This entry module exports the finite labelled-tree state space, grafting and its quotient transition, and the binary Rémy specialization at α = 2.

References: P. Marchal, A note on the fragmentation of a stable tree, DMTCS Proc. (2008); N. Curien and B. Haas, The stable trees are nested, arXiv:1207.5418, §§1.1, 1.3. The exact law formula and the uniform binary law at α = 2 are proved separately.