This requires a few pieces:
* Make node tags use `Fin n` intead of natural numbers. This makes
it possible to build a finite lattice over AST nodes, and also
ensure automatic, total indexing from CFG nodes into the AST that
created them. For this, use the elaborator to derive the ordering
statements etc. where possible.
* Adjust the forward framework to enable proofs that don't just state
correctness on the environment, but also on an arbitrary additional
state accumulated from traversing the trace.
* State the reaching definition analysis's correctness in terms
of this new framework.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
- Wrap the forward-analysis framework in a Spa.Forward namespace so its
generic names (analyze, result, joinAll, variablesAt, ...) no longer
sit flat in Spa, matching the ConstAnalysis/SignAnalysis convention.
- Merge the split Graph namespace in Graphs.lean by relocating buildCfg.
- Use nested namespace Spa / Fixedpoint instead of Spa.Fixedpoint.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The port had flattened Agda's instance arguments ({{flA}}, {{evaluator}},
{{latticeInterpretation}}, {{validEvaluator}}) into explicitly threaded
values (fhL, E, I, hE). Restore them as typeclasses:
- Spa.FiniteHeightLattice: now actually used — Fixedpoint takes the
instance instead of a FixedHeight value; FiniteMap gets the missing
instance (height = ks.length * height B), so varsFixedHeight /
statesFixedHeight / signFixedHeight / constFixedHeight plumbing
disappears (instance bottoms are defeq to the old ones)
- Spa.Analysis.Forward.Evaluation: StmtEvaluator/ExprEvaluator become
classes; the Valid* Props become Prop-classes, as in Agda
- Spa.Analysis.Forward.Adapters: the expr→stmt adapter and its validity
are instances (Agda: the ExprToStmtAdapter instances)
- LatticeInterpretation is a class; sign/const interpretations,
evaluators and validity proofs are instances; use sites read like the
Agda module applications: result SignLattice prog
Proof simplifications (same theorems, proofs factored):
- Spa.Lattice.AboveBelow.monotone₂_of_strict: any ⊥-strict/⊤-dominated
operation on a flat lattice is monotone — replaces the four near-
identical case bashes per analysis (postulates in Agda)
- Spa.Lattice.AboveBelow.interp_sup_of/interp_inf_of: the shared flat-
lattice interpretation case analysis, making interpSign_sup/inf and
interpConst_sup/inf one-liners
lake build green with zero warnings; lake exe spa output verified
byte-identical (diff) to the previous, Agda-verified output.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
- Spa.Analysis.Forward.Lattices: VariableValues/StateVariables (FiniteMap
instantiations), fixed heights, variablesAt, joinForKey/joinAll, interpV
and its sup/foldr lemmas
- Spa.Analysis.Forward.Evaluation: StmtEvaluator/ExprEvaluator + validity
(the Agda Valid* instance records become plain Props)
- Spa.Analysis.Forward.Adapters: expr-to-stmt evaluator adapter + validity
- Spa.Analysis.Forward: updateAll, analyze, result (least fixpoint via the
gas-based Fixedpoint), walkTrace, analyze_correct — the framework's main
soundness theorem
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
