Bienaymé trees: definitions #
Section 2.1 of the paper (source lines 679–713). An offspring law is a probability mass
function μ on ℕ. The Bienaymé tree law gives a finite plane tree T the weight
∏_{u ∈ T} μ_{k_u(T)}. That the weights sum to one for a critical μ with μ 1 ≠ 1
(normalization, i.e. almost sure finiteness of the tree) is a theorem proved in
PoissonDeclumping.Bienayme.Normalization, not part of the definition.
The definitions IsCritical, PlaneTree.weight, PlaneTree.bienayme, PlaneTree.Admissible
and PlaneTree.conditioned are in PoissonDeclumping.Statements.Defs, which originate in the
upstream statement contract; this module only re-exports them under its historical name.