ASPf-next 0.2.0a1

ASPf-next 0.2.0a1

Release date: 2026-08-08

Experimental alpha research software.

ASPf-next is an independent clean-room modernization of Marcello Balduccini's ASP{f} language. This first published alpha provides an inspectable Python compatibility frontend and reference translation for Clingo 5.8. It does not modify Clingo, copy historical Clingo{f} implementation code, claim full compatibility, or reproduce the historical system's grounding efficiency.

Why 0.2.0a1?

The repository began with unpublished 0.1.0a1 metadata for a restricted reference frontend. The 0.2 line reflects three completed historical compatibility milestones: global #nherb. mode, historical non-Herbrand visibility directives, and historical seed-equality safety with ordinary value variables. The alpha suffix remains because the language boundary is narrow and the backend is still a correctness-oriented translation.

Highlights

• Partial non-Herbrand applications: absence means undefined, while a global functionality constraint prevents conflicting values.
• Explicit, application-style, and global declaration forms with exact name/arity handling.
• #= assignments in facts and complete rule heads.
• Defined-value #=, #!=, and integer-only #<, #<=, #>, #>= body comparisons, including application operands.
• One-level default negation implemented as failure of positive satisfaction, including undefined operands.
• Direct domain-safe ordinary key variables, scalar seed-equality safety, and restricted body value variables.
• Historical assignment visibility controls that affect rendering only.
• Stable human and JSON models with private __aspf_ predicates filtered.
• An executable historical compatibility corpus and manifest-derived report.
• A synthetic partial-indicator portfolio demo that demonstrates undefinedness without making a trading or predictive claim.

Historical compatibility status

The 39-case historical corpus has 35 passing cases and 4 strict expected unsupported cases. Within the full manifest classification, 7 passing cases carry a documented restriction, 2 passing cases reproduce historical rejection of invalid programs, 4 cases are intentionally deferred, and none are unresolved. Run:

pytest tests/historical_compat
python scripts/compatibility_report.py

The compatibility policy and case-level evidence are in the historical audit.
The release boundary also passed the documented 20-point adversarial semantic review.

Non-Herbrand variable decision

Historical _V n-variables remain deferred. The research probe found that an ordinary relational rewrite can reproduce simple copy models only by grounding over each candidate value, while treating _V as a constant is semantically wrong. The reference backend therefore fails the required grounder-inert and grounding-growth criteria. See the NO-GO analysis.

Known limitations

• no arithmetic expressions inside n-atoms;
• no n-atoms in aggregates, choices, disjunctions, or conditional literals;
• no _V non-Herbrand variables;
• no nested non-Herbrand application operands;
• no ordered value variables or assignment-head value variables;
• no native theory-atom backend or custom propagator; and
• no claim of full ASP{f}/Clingo{f} compatibility or historical grounding efficiency.

Install and verify

Python 3.11 or 3.12 is supported.

python -m pip install .
aspf examples/01_basic_assignment.aspf
aspf examples/portfolio/technical_indicators.aspf

Attribution

Marcello Balduccini created ASP{f} and the historical Clingo{f} system.
ASPf-next is independently created and maintained by Dylan Flynn and is not affiliated with Balduccini, the historical project, Potassco, or Potassco's separate Flingo project. See the provenance policy.

---

Licensing note: ASPf-next 0.2.0a1 was released under the MIT License and remains governed by the MIT License included in this tag. Rights granted for this release are unchanged. Later ASPf-next versions may be distributed under different terms; consult the license accompanying the specific version you use.