ASPf-next 0.2.0a2

ASPf-next 0.2.0a2

Release date: 2026-08-22

Experimental alpha research software.

ASPf-next 0.2.0a2 is a hardening release. It does not expand the released
ASP{f} syntax or expose the native research backend. The reference backend
remains the production/default implementation, and historical _v
non-Herbrand variables remain unsupported by the frontend.

Highlights

• Added aspf --version and a clean-wheel installation smoke check.
• Adversarially tested native research provenance, narrow clauses,
  backtracking, repeated solves, multi-model enumeration, and bounded
  multi-thread behavior.
• Added a deterministic 144-case reference/native differential matrix and
  metamorphic rule/seed-order checks.
• Corrected fallback-clause lifetime handling and made thread-local evaluation
  cache validity explicit through semantic generation tracking.
• Added deterministic clause-audit records and conservative explanations for
  dynamically absent applications only when all grounded providers have
  justified failures.
• Tightened conservative non-ground n-loop matching without broadening the
  documented exact fragment.
• Recorded before/after native workloads and kept the prototype's
  substantially slower solve performance explicit.

Compatibility boundary

The supported-language specification, reference lowering, CLI backend, and
normalized output contract are unchanged from 0.2.0a1. In particular:

• undefined is not zero, false, unequal, or a guessed value;
• functionality does not imply totality;
• arithmetic and n-atoms in aggregates, choices, disjunctions, and conditional
  literals remain unsupported;
• _v remains rejected rather than translated into an ordinary Clingo
  variable; and
• the native backend remains under research/, with a PARTIAL GO for further
  research and a NO-GO for production integration.

License transition

Beginning with this release, ASPf-next is distributed under the PolyForm
Noncommercial License 1.0.0. It is source available, not OSI-approved open
source. Commercial use requires prior written permission or a separate
commercial license from the copyright holder.

ASPf-next 0.2.0a1 was released under the MIT License. Rights granted under
that release remain governed by its accompanying MIT License. The transition
for later versions does not revoke or narrow those historical rights. See the
licensing guide.

Other repository revisions validly obtained with an MIT License before the
transition likewise retain the rights granted with those copies.

Known research limitations

• Dynamic absence is explained only when every grounded provider has a proved
  failure; unassigned and cyclic providers deliberately remain unexplained.
• Native closure evaluation is still Python-heavy and substantially slower
  than the relational reference backend on recorded workloads.
• The exact typed n-loop fragment is variable-free; broader non-ground analysis
  remains conservative.
• Two-thread behavior has bounded test evidence, not a production support
  claim.

Validation

The full quality, conformance, historical-compatibility, research,
package-build, and clean-install checks passed before publication. The
maintainer approved the licensing transition after its limitations and
non-retroactivity were documented.