eyeprolog

ISO/IEC 13211-1 compliance ledger

This ledger is the release-facing audit and high-level coverage map for EyeProlog’s ISO/IEC 13211-1 core. The normative baseline is ISO/IEC 13211-1:1995 together with Technical Corrigenda 1:2007, 2:2012, and 3:2017. Detailed row-level evidence lives only where it adds information: the built-in, processor, term-semantics, Prolog-text/execution, evaluable-functor, implementation-defined, WG17-syntax, and STC draft ledgers in this directory. The generated conformance-report.md gives the current executable WG17 syntax result together with file-based case totals.

The ledger deliberately does not claim independent certification. A row marked covered means EyeProlog has implementation and executable tests for that family and no known open defect in the listed behavior. A row marked audit means the family is implemented and tested, but the project has not yet mapped every normative shall, option combination, prescribed error, and relevant implementation-dependent overlap choice to an explicit audit outcome.

Processor compliance requirements

Requirement Status EyeProlog evidence / remaining work
5.1(a) prepare conforming Prolog text covered Clause 6 token/term production and rejection families are mapped by the strict production gate and the complete 372-case vendored WG17 syntax matrix; 7.4 preparation/directive behavior is separately closed.
5.1(b) execute conforming Prolog goals covered Clause 7 term/control/execution semantics, the higher-level 7.10 stream model, 7.11 flags, the 7.12 error envelope, all 8.2-8.17 built-in rows, and Clause 9 arithmetic have explicit executable dispositions.
5.1(c) reject nonconforming text/read-terms covered WG17 negative syntax cases, focused malformed-production/escape/comment/operator cases, read-term syntax errors, and strict rejection of implementation-specific syntax provide explicit rejection evidence across the Clause 6 families.
5.1(d) document permitted variations covered The clause-by-clause ISO 5.4 decision index records every explicit implementation-defined decision found in the Part 1 + Corrigenda baseline and separately inventories implementation-specific extension families. The index retains an audit gap category for future discoveries; no current release-facing row depends on one.
5.1(e) offer a strictly conforming mode covered --iso-strict and API option isoStrict: true restrict the processor to the Part 1 + Corrigenda 1-3 core language surface, remove EyeProlog-only registry/flag/operator features, disable automatic tabling/recursion guards, and reject the normal-profile host stringTerm/1 term type at strict program/goal entry.
5.4 accompanying documentation covered The Art of EyeProlog remains the implementation reference; ISO-IMPLEMENTATION-DEFINED.md is the closed clause-by-clause 5.4 decision index and points each decision to implementation evidence.
5.5 extension boundaries covered ISO-PROCESSOR-REQUIREMENTS.md gives an explicit disposition for every 5.5 extension hook. The Clause 6 cross-profile gate verifies that normal-mode syntax extensions do not reinterpret standard text accepted by the strict reader.

Normative language families

Standard area Status Current evidence
Clause 6 — tokens, terms, lists, operators, quoted text covered The strict Clause 6 gate maps atomic/variable/compound/operator/list/curly/double-quoted term forms, layout/comments, quoted escapes, integer bases/character codes, floating tokens, and solo/meta token boundaries, with malformed counterparts rejected. The complete 372-case WG17 syntax matrix provides independent production-level coverage, and a cross-profile gate verifies that normal syntax extensions preserve every strict-accepted standard observation. The implementation-defined 6.5/6.6 PCS/collation choices are documented separately.
7.1-7.3 — term types, term order, unification covered ISO-TERM-SEMANTICS-MATRIX.md records the five mutually exclusive strict term types, derived variable/compound/list notions, the complete standard-order classes and implementation-dependent variable-order choice, NSTO MGU/failure behavior, and EyeProlog’s permitted consistent occurs-check failure for Part 1’s undefined STO ordinary-unification cases. The normal JavaScript API string term is documented as a 5.5.4 extension and rejected at strict program/goal entry.
7.4 — Prolog text and directives covered ISO-PROLOG-TEXT-EXECUTION-MATRIX.md closes the preparation/directive rows: declaration semantics, source clauses, cross-text operators/character conversion/flags, initialization order/lifetime, include/1, and one-time ensure_loaded/1, with implementation-defined cross-text choices indexed under 5.4.
7.5-7.6 — database and term/clause conversion covered ISO-PROLOG-TEXT-EXECUTION-MATRIX.md closes static/dynamic and private/public procedure semantics, clause order, logical-update visibility, empty/unknown lifetime, and term/body/clause conversion. Source and runtime assertion conversion recurse through ,/2, ;/2, and ->/2, preserve variable identity, and protect standardized static/control procedures.
7.7 — execution and backtracking covered ISO-PROLOG-TEXT-EXECUTION-MATRIX.md closes ordinary clause selection/backtracking, source/database order, empty-versus-unknown procedures, logical-update visibility, and strict dispatch. EyeProlog automatic tabling, cycle guards, and recursive numeric shortcuts remain disabled in the strict profile.
7.8 — control constructs and exceptions covered ISO-PROLOG-TEXT-EXECUTION-MATRIX.md closes true/0, fail/0, call/1, cut, conjunction, disjunction, if-then(-else), and catch/3/throw/1, including Corrigendum 2 catchability of errors arising from the protected goal and Corrigendum 3 term-to-body conversion at call/1 entry; the regression suite pins the resulting cut scope when an initially unbound variable goal later becomes !. The 8.15 built-in additions remain independently row-audited.
7.9 — expression evaluation covered ISO-EVALUABLE-FUNCTOR-MATRIX.md closes recursive evaluation, direct-variable precedence, corrected non-evaluable F/N errors (including STC #69), operand template/type rules, mixed arithmetic-comparison conversion, exceptional values, and finite-host resource normalization. The audit also fixes float-only float_integer_part/1 and float_fractional_part/1 so even huge valid integers reach type_error(float,...) before any I->F overflow.
7.10 — input/output concepts covered Higher-level stream semantics are pinned for non-atom ground stream terms, alias lifetime, current/target stream selection and fallback, write truncation, append positioning, contradictory stream options, exact binary round-tripping, flushing, standard-stream close behavior, and repositioned overwrite. Term-output spelling is also checked lexically where ISO distinguishes token forms: Corrigendum 2 bar operators are written with bare |, ordinary atom/functor | remains quoted, and the semicolon name token is emitted bare by canonical output. The complete 8.11-8.14 built-in mode/error family remains row-audited in ISO-BUILTIN-MODE-ERROR-MATRIX.md, while all implementation-defined stream choices are indexed in ISO-IMPLEMENTATION-DEFINED.md.
7.11 — flags covered The complete Part 1 flag set, selected defaults, standard value domains, changeability, current_prolog_flag/2, and set_prolog_flag/2 error behavior have dedicated strict tests. EyeProlog selects bounded=false and integer_rounding_function=toward_zero; valid alternative values of those fixed flags reach permission_error(modify,flag,...), while max_integer and min_integer have no current value. STC #70 is recorded explicitly: EyeProlog has no separate finite procedure-arity ceiling, so the optional max_procedure_arity flag is absent while max_arity remains unbounded. Strict mode excludes the EyeProlog occurs_check extension.
7.12 — errors covered The strict error-envelope gate exercises instantiation, type, domain, existence, permission, representation, evaluation, resource, syntax, and system errors through error(Error, Context). Built-in rows provide the individual prescribed conditions, implementation-defined representation/context choices are documented, and simultaneous-error regressions pin deterministic EyeProlog choices without treating textual table order as normative.
8.2-8.17 — built-in predicates covered ISO-BUILTIN-MODE-ERROR-MATRIX.md now records the complete Part 1 + Corrigenda built-in family at one row per prescribed mode, success/failure behavior, individual error condition, and conditional/not-applicable branch. The row audit exposed and fixed source/runtime 7.6.2 body conversion/variable sharing, strict host-string leakage, input-code error timing, close/2 force handling, and closed-stream stream_property/2 behavior. Simultaneous-error choices are documented as implementation dependent under 7.12 unless separately constrained.
Clause 9 — evaluable functors covered ISO-EVALUABLE-FUNCTOR-MATRIX.md records the published Part 1 + Corrigenda arithmetic templates and exceptional branches across 9.1, 9.3, and 9.4. It pins the unbounded integer model, rndI/rndF/resultF choices, float-only conversion rules, I->F overflow, explicit exp/1 and power underflow, Corrigendum 2 additions and mixed-type max/2/min/2 implementation-dependent choice, Corrigendum 3 negative-power correction, signed bitwise/shift choices, and resource-error translation. Post-N289 STC #75 remains a separately tracked draft proposal rather than a silent change to the published baseline.
Corrigendum 1 covered Double-quoted atom/operator-priority corrections have dedicated cases.
Corrigendum 2 covered Added predicates/functors, catch corrections, bar/operator and uninstantiation corrections have dedicated cases, including the distinct bare | operator token required for term output.
Corrigendum 3 covered Writer options, variable_names/1, canonical list output and negative-power corrections have dedicated cases.

Conformance corrections and audit closure

The audit against the licensed Part 1 text and Corrigenda closed two concrete mismatches that are now part of the closed Part 1 audit:

A follow-on audit made the processor-character-set/collation choices explicit. A follow-up processor-character-set review corrected an over-strict interpretation: because PCS membership and extended-character classification are implementation defined by Part 1, --iso-strict must not replace EyeProlog’s ordinary processor choice. Both profiles now use Unicode scalar values as PCS members and collating integers; Unicode letters/white-space/graphics receive documented extended lexical classes, while surrogates and values above U+10FFFF remain representation errors. Strict mode continues to reject implementation-specific facilities without changing these implementation-defined character choices. The complete WG17 syntax matrix remains a release gate.

The subsequent arity audit originally selected a finite max_arity=65535, but the post-Corrigendum STC arity review exposed that as the wrong abstraction: Part 1 max_arity is the maximum arity of compound terms, not a procedure-arity limit. EyeProlog now again selects max_arity=unbounded and removes the artificial 65535 checks from source parsing, functor/3, =../2, predicate indicators, and Corrigendum 2 call/N closure expansion. Practical host exhaustion remains a resource condition rather than a declared term-arity boundary. Focused strict tests also lock the corrected 8.5 term-construction errors, selected 8.8 clause-access and 8.10 all-solutions overlap behavior, database update errors, and Corrigendum 3 variable metadata traversal/write naming.

The public WG17 number_chars/2 comparison used in preparation of Corrigendum 2 has additionally been checked during the audit. It remains supporting review evidence rather than a duplicated vendored corpus or release criterion.

The flag and term-I/O audit closes the Part 1 flag family and tightens the 8.14 term-I/O/operator error rules. The strict flag registry now distinguishes a standard value that is valid but not selectable from a value outside the standard domain: attempts to change fixed bounded or integer_rounding_function to another standard value therefore reach the required permission error. read_term/3, write_term/3, op/3, and current_op/3 now cover their required error conditions individually and keep EyeProlog’s chosen simultaneous-error behavior stable. Section 7.12 makes that choice implementation dependent when several error conditions hold at once. Strict write_term/2-3 accepts only the Part 1 plus Corrigendum 3 option surface; the normal-profile double_quotes/1 and spacing/1 write options remain explicitly documented implementation-specific EyeProlog extensions.

The preparation, stream, conversion, sorting, and arithmetic audit expands the coverage into Prolog-text, stream, atomic-conversion, sorting, and arithmetic edge cases. Strict preparation now enforces the Part 1 declaration constraints for dynamic/1, multifile/1, and discontiguous/1, including cross-text multifile use and one-time initialization per prepared program. Stream handling now distinguishes text and binary permission errors, validates stream properties and stream-term requirements, and tightens creation, truncation/append, repositioning, flush, EOF, close, and current-stream behavior. Corrigendum 2 keysort/2 variable and non-pair errors are corrected. Strict arithmetic no longer exposes the EyeProlog-only evaluable atom e, while the Corrigendum arithmetic additions remain available. These corrections are retained as regression evidence inside the closed shall-by-shall/error-condition audit.

The next Corrigendum 2 pass closed the prescribed call/2..8 max-arity branch for processors with a finite max_arity, and corrected reverse atom_chars/2 / atom_codes/2 improper-list culprits. With EyeProlog’s selected max_arity=unbounded, the conditional call/N representation_error(max_arity) branch is intentionally unreachable unless a future processor profile selects a finite compound-term limit; closure expansion itself remains covered by strict regressions.

The following Part 1 pass tightens more of the still-open prescribed-error and arithmetic matrix. arg/3, atom_concat/3, sub_atom/5, number_chars/2, number_codes/2, and char_conversion/2 now cover their individual standard error conditions and retain deterministic EyeProlog choices for overlapping conditions; 7.12 explicitly leaves such simultaneous-error selection implementation dependent unless another rule constrains it. Corrigendum 2 partial versus improper list distinctions are applied consistently to atomic and number conversion. Clause 9 strict evaluation now gives the prescribed number/integer operand diagnostics, checks direct-variable instantiation first, enforces the float-only input modes of floor/1, truncate/1, round/1, and ceiling/1, and reports zero raised to a negative power as undefined. Finally, strict mixed integer/float arithmetic comparisons perform the Part 1 integer-to-float conversion (including float_overflow); normal EyeProlog keeps its exact cross-type comparison as an extension. Dedicated strict regressions cover these distinctions without changing the normal-profile arithmetic error contract.

A further Clause 9 pass closes the floating conversion and exceptional-value boundary exposed by unbounded integers. Strict floating evaluable functors now perform the required integer-to-float conversion before invoking the host math operation, so an integer outside the selected finite binary64 range reports evaluation_error(float_overflow) rather than producing a secondary host-math result. The explicit underflow clauses for exp/1, Part 1 **/2, and Corrigendum 2 ^/2 are enforced even though EyeProlog retains the implementation-defined round(x) choice for generic resultF arithmetic. The power audit also preserves the specified negative-base and zero/negative exception conditions before any later I->F overflow, including Corrigendum 3’s correction to the **/2 operand wording and Corrigendum 2’s distinct rule that ^/2 may accept an integer-valued float exponent.

A subsequent 8.11/8.12 pass closes two stream-option/error-overlap details. For get_code/1-2 and peek_code/1-2, a fixed integer which is not an in-character code is now diagnosed only after the earlier stream existence/direction/text-vs-binary/past-EOF and input-entity conditions, so it cannot mask the stream error prescribed by the published table. close/2 now also treats force(true) as a presence-based option exactly as 8.11.6.1(a) describes: a later force(false) does not cancel an earlier force(true) when a Resource Error or System Error occurs during closure. Focused strict tests cover both overlap families.

The row-level matrices make the exit criteria concrete rather than leaving conformance as a broad test-count claim. ISO-BUILTIN-MODE-ERROR-MATRIX.md now records each prescribed mode/error row for the 8.2-8.5 and 8.15-8.17 slices, and ISO-PROCESSOR-REQUIREMENTS.md decomposes the Clause 5 obligations into covered, audit, and not-applicable decisions. While doing that mapping, the 7.6.2 term-to-clause conversion audit exposed a runtime assertion defect: variables and invalid terms nested under ;/2 or ->/2 were not being recursively converted. asserta/1 and assertz/1 now convert all three standardized binary control forms ,/2, ;/2, and ->/2 recursively, so nested variables become call/1 and a non-callable nested branch is rejected at assertion time with the complete clause-body culprit.

The Clause 5 decomposition also exposed an embedding-only type boundary that source-text tests could not see. EyeProlog’s normal JavaScript API deliberately exports stringTerm(Text) as an implementation-specific additional term type. Its normal-profile ordering, conversion, evaluation, and writing behavior is now documented under 5.5.4, while strict Program construction and strict Solver goal entry reject such terms with representation_error(term). This keeps the host extension available in normal mode without allowing it to become a sixth term type in the Part 1 strict execution domain.

A row-level 8.6-8.10 pass then turns arithmetic predicates, clause/database operations, and all-solutions predicates into explicit mode/error-condition entries. During that audit, strict source preparation exposed a 7.6.2 defect: a clause such as foo(X) :- X. was executed as a variable goal but was not stored in the converted call(X) form, so clause(foo(C),call(C)) and the corresponding retract/1 pattern lost the required head/body variable identity. Strict preparation now performs the same recursive body conversion used by runtime assertion while preserving the original variable objects. The pass also records the 7.12 rule for simultaneous errors, so deterministic overlap tests are treated as processor choices unless more specific normative text constrains them.

The subsequent 8.11-8.14 pass completes the built-in row audit. Stream selection/control, character/code input and output, byte I/O, term I/O, operators, and character conversion now each have explicit success/mode and individual-error outcomes in ISO-BUILTIN-MODE-ERROR-MATRIX.md. During this pass stream_property/2 exposed a lifecycle distinction: a syntactically valid stream-term for a stream that has been closed denotes no currently open stream property pair and therefore fails, whereas a term that is not a stream-term is still a domain_error(stream, ...). The higher-level Clause 6, 7.10, and 7.12 gates now close those surrounding processor requirements as well, so the built-in table participates in a fully dispositioned release-facing ledger.

Post-Corrigendum STC cross-check

The public WG17 STC draft is tracked as useful defect-discovery material, but it is not silently treated as a fourth published Corrigendum. The current audit confirms EyeProlog already has the behavior implicated by the substantive STC items on negative-number layout/operator syntax, arithmetic instantiation precedence, EOF actions/end tokens, character/code/byte output error overlap, clause head/body variable identity, sequential op/3 and set_prolog_flag/2 preparation effects, integer-to-float transcendental evaluation, char_code/2 type precedence, read_term/3 EOF handling, mixed arithmetic comparison, integer_rounding_function=toward_zero, set_prolog_flag/2 variable errors, and bagof/3 answer order. STC #21 is also used to keep finite-host exhaustion of unbounded integer operations inside the Prolog resource-error model.

The newer STC arity discussion clarifies that max_arity describes compound terms. EyeProlog therefore selects unbounded and does not invent a finite predicate/procedure ceiling merely to preserve the former 65535 value. STC #56, which became a WG17 action item, is implemented narrowly for database protection: (:-)/1-2 are static/private for modification and clause/2 access, while ordinary calls retain their separate existence behavior. The 2026-08-23 post-N289 draft adds four more executable review points. STC #73 confirms the draft max_float / min_float representation-limit shape for read/1-2 and read_term/2-3; STC #74 extends the same distinction to number_chars/2 and number_codes/2; STC #76 proposes the representation_error(character) already exercised by EyeProlog’s invalid-UTF-8 read regressions. STC #75 is deliberately different: it proposes changing the published power-underflow conditions so that they depend on the 9.1.4.2 resultF choice. Because that proposal is not a published Corrigendum, strict mode keeps the licensed Part 1/Corrigendum 2 power errors while the draft divergence is pinned and documented.

Other draft/editorial or deliberately controversial proposals (for example deleting standalone if-then) remain outside the Part 1 + Corrigenda 1-3 strict baseline until standardized or adopted as an explicit compatibility extension.

Strict-core boundary

isoStrict: true is intentionally a Part 1 + Corrigenda 1-3 mode. It does not interpret the following as core-language features:

The predefined Part 1 1200 fx ?- operator and 1200 xfx --> operator remain ordinary operator syntax in strict core mode. A conforming op/3 directive may still add an infix ?- definition; strict mode reads that as an ordinary term rather than as a quad.

Module and DCG compatibility features remain supported and tested in the normal EyeProlog profile, but they are not folded into the Part 1 strict-core claim. The project does not currently assert that this evidence closes every requirement of ISO/IEC 13211-2:2000 or ISO/IEC TS 13211-3.

Release gate

A release intended to advance ISO conformance must pass all of:

npm test
npm run test:iso-strict
npm run test:conformance
npm run test:wg17

The unified npm test gate includes the strict-core suite. Expected conformance outputs are never auto-accepted.

Exit criteria for a full conformance claim

The Part 1 audit is closed by explicit dispositions, not by a test-count threshold. The table below records the closure criteria used by the project. A covered status is an implementation/audit result, not an independent certification. Public post-N289 STC drafts remain review input until standardized.

Criterion Status Evidence
Clause 5 processor obligations have explicit dispositions covered ISO-PROCESSOR-REQUIREMENTS.md gives explicit outcomes for 5.1-5.5, including the strict/normal extension boundary.
Clause 6 lexical/syntactic requirements have explicit dispositions covered the strict Clause 6 production/rejection gate and the 372-case vendored WG17 matrix cover the standard families; cross-profile preservation verifies that normal extensions do not reinterpret strict-accepted text.
Clause 7 semantic requirements have explicit dispositions covered 7.1-7.12 now have explicit semantic, implementation-defined, or error-envelope dispositions backed by strict tests and the specialized matrices.
Clause 8 built-in modes/errors have explicit dispositions covered ISO-BUILTIN-MODE-ERROR-MATRIX.md closes 8.2-8.17 row by row
Clause 9 evaluable-functor requirements have explicit dispositions covered ISO-EVALUABLE-FUNCTOR-MATRIX.md plus the strict arithmetic regression closes the published Part 1 + Corrigenda arithmetic rows
Implementation-defined choices are documented covered ISO-IMPLEMENTATION-DEFINED.md is the Clause 5.4 decision index and strict tests pin execution-visible choices
Implementation-specific strict/normal boundary is documented and tested covered all 5.5 hooks have explicit dispositions; the WG17 cross-profile gate verifies syntax-preservation for standard text accepted by the strict reader.
Published Corrigenda 1-3 are incorporated covered dedicated conformance/strict tests and this ledger track all three published Corrigenda
Current post-N289 draft is tracked without silently changing the published baseline covered STC-DRAFT-STATUS.md tracks reviewed draft items separately from normative requirements
Independent external syntax corpus is an offline release gate covered the vendored WG17 syntax matrix has 372 executable dispositions checked against its upstream expectations
Third-party standard-core regression provenance is retained covered adapted Logtalk, Scryer, Trealla, and SWI-Prolog cases retain source identifiers and licenses in THIRD_PARTY.md
No unexplained deviation remains in the release-facing ledger covered the release-facing ledger contains no remaining audit rows; documented variation points are implementation-defined/specific or draft-only rather than unexplained deviations.

The specialized row matrices are evidence for this ledger, not separate public status documents. The Art of EyeProlog remains the implementation reference.

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