Module order2_graph 

Compiled value/gradient/Hessian lowering for runtime row expressions.

Order2Graph implements the same RuntimeJetScalar algebra as the eager packed jets, but records a small scalar DAG instead of propagating a dense Hessian through every intermediate. Each node carries its value and primary gradient. Once the scalar output is known, one reverse sweep computes node adjoints and accumulates each nonlinear node’s local curvature exactly once.

This is the universal second-order chain rule for a scalar DAG. Families own only their one generic row expression and certified unary derivative stacks; this module owns the compiled lowering schedule.

Structs

Order2Graph

Const-primary scalar handle into an Order2GraphWorkspace.

Order2GraphWorkspace

Reusable storage for a compiled scalar DAG.