proof
P21 Transport gain
Lean spine source
formal/AlignmentProofSpine/Bundles.leanFrom the machine-checked spine in formal/ (core modules are Mathlib-free;Field/Finite/ may import Mathlib). Not self-contained for Lean 4 Web — use the repo or a local lake build.
theorem P21_transport_gain_prefers_transport_model
(h : Gain TransportModel BaselineModel > 0) :
Preferred TransportModel BaselineModel :=
S07_mdl_positive_gain_preferred TransportModel BaselineModel h