α-CROWN Graph Transfer Soundness #
Pointwise soundness theorem for the graph-dialect alphaCrownStepNode? transfer rule. The proof
dispatches on the node kind to the per-operator lemmas in the Alpha subdirectory: leaf nodes
(Alpha.Leaf), value-preserving nodes (Alpha.Shape), linear nodes (Alpha.Linear), ReLU
(Alpha.ReLU), and the IBP-derived constant fallback (Alpha.Fallback).
Main transfer theorem #
Pointwise soundness of the graph-dialect α-CROWN transfer rule.
Fix a graph g, parameters ps, an input point x, and a locally consistent value semantics
array vals (that is, vals[id] agrees with evaluating node id from its parents' values).
Assume:
- the designated input node in
inputsmatchesx(InputsMatch), - the IBP boxes
ibpenclose the semantic values invals(IBPEnclosesVals), and - the α parameters are well-formed (
AlphaOK).
Then the concrete step function alphaCrownStepNode? satisfies the abstract
CrownTransferSound requirement: whenever every parent p is enclosed by its certificate entry,
the current node id is enclosed by the step-produced certificate entry as well.
This is the key lemma that lets alphaCrownStepNode? plug into the generic end-to-end checker
theorem in NN.MLTheory.CROWN.Proofs.GraphCrownCertSoundness.