V0.27 Scope - Multi-Generator Diagnostics Decision#

Status: COMPLETE

Summary#

v0.27 is a multi-generator diagnostics decision release.

Stable investigation path:

canonical scalar 1D periodic FieldBatch
-> residual evaluator
-> supplied multi-row GeneratorFamily
-> algebraic diagnostics + PDE-context diagnostics + fit probe diagnostics
-> explicit public promotion decision

Release conclusion:

multi_generator_diagnostics_feasible_fitting_deferred

The release separates:

  • algebraic_diagnostics: span, rank, closure, brackets, and structure constants

  • pde_context_diagnostics: whether generator/PDE pairs are meaningful and empirically checked

  • fit_probe_diagnostics: internal-only recoverability probes

  • public_promotion_decision: whether any public API promotion is justified

Closure does not imply PDE residual symmetry.

Public API Notes#

New submodule-only runtime example:

  • pdelie.examples.run_multi_generator_diagnostics_example(...)

  • python -m pdelie.examples.multi_generator_diagnostics

Behavior updates to existing public diagnostic helpers:

  • pdelie.symmetry.diagnose_generator_family_closure(...) now reports well-formed rank-deficient families as diagnostic reports instead of raising solely because the rows are redundant.

  • pdelie.symmetry.compare_generator_spans(...) now reports zero-rank or rank-deficient span comparisons as failed/warning reports instead of crashing for well-formed families.

  • pdelie.symmetry.validate_symmetry_candidate(...) now accepts closure_required=True|False for GeneratorFamily candidates.

No new public multi-generator fitting API, finite-flow API, invariant-chart API, orbit builder, BCH composition API, exponential-map flow integration, group-action atlas, or root export was added.

Frozen Semantics#

Bracket convention:

[X_i, X_j] = X_i · ∇X_j - X_j · ∇X_i

Structure constants:

[X_i, X_j] = sum_k C[i, j, k] X_k

Frozen diagnostic labels:

  • algebraic_diagnostics_feasible

  • pde_context_validation_diagnostic_only

  • fit_probe_diagnostic_only

  • multi_generator_diagnostics_feasible_fitting_deferred

  • multi_generator_fitting_candidate_for_future_promotion

  • deferred_no_go

Frozen PDE-context labels:

  • known_pde_symmetry

  • algebraic_only

  • blocked_no_finite_transform

  • blocked_parameter_policy

  • failed_residual_preservation

  • not_meaningful_for_pde

Rank policy:

  • malformed family -> typed validation error

  • well-formed rank-deficient family -> diagnostic status with family_rank_status = "rank_deficient"

  • rank-deficient reference/span comparison -> failed or warning report

Algebraic Diagnostic Matrix#

v0.27 records exact supplied-family evidence for:

  • abelian_two_translation_family: X1 = ∂x, X2 = ∂t

  • affine_x_family: X1 = ∂x, X2 = x∂x, [X1, X2] = X1

  • affine_u_family: X1 = ∂u, X2 = u∂u, [X1, X2] = X1

  • nonclosed_polynomial_family: X1 = ∂x, X2 = x^2∂x, [X1, X2] = 2x∂x outside the span

  • rank_deficient_affine_family: redundant rows such as X1 = ∂x, X2 = 2∂x

  • basis_mismatch_family: same apparent rows under incompatible basis specs

Explicit Non-goals#

  • no public multi-generator PDE fitting

  • no multi-generator invariant charts

  • no finite multi-generator flows

  • no BCH composition

  • no exponential-map finite-flow integration

  • no multi-parameter orbit charts

  • no group-action atlas

  • no operator-facing APIs

  • no neural or callable generator APIs

  • no root export expansion

  • no train/test policy or leakage prevention

  • no broad adapters or file loaders

  • no multidimensional or nonuniform stable support

Milestone Status#

  • Milestone 0: COMPLETE

  • Milestone 1: COMPLETE

  • Milestone 2: COMPLETE

  • Milestone 3: COMPLETE

  • Milestone 4: COMPLETE

  • Milestone 5: COMPLETE

  • Milestone 6: COMPLETE

Release Gate#

v0.27 is complete only if:

  • supplied closed families report expected structure constants under the frozen bracket convention

  • non-closed families report nonzero closure residuals

  • rank-deficient well-formed families return diagnostic reports, not automatic exceptions

  • multi-row candidate validation separates algebraic evidence from PDE-context evidence

  • the public example is diagnostic-only and performs no fitting

  • no public multi-generator fitting, finite-flow, BCH, invariant-chart, orbit-chart, operator, neural/callable, or root export surface lands

  • CI uses one compact current release gate plus full editable tests and package smoke

  • package-index publishing remains deferred until v1.0 or later