{ "_id": "6ac17687552a13804ac7f560", "Package": "sezgi", "Title": "Metaheuristic Optimization with a 'Rust' Core", "Version": "0.1.6", "Authors@R": "c(\nperson(\"Tolga\", \"Berber\", email = \"tolga.berber@fen.ktu.edu.tr\",\nrole = c(\"aut\", \"cre\"),\ncomment = c(ORCID = \"0000-0002-6487-5581\")),\nperson(\"Beyzanur\", \"Siyah\", role = \"aut\",\ncomment = c(ORCID = \"0000-0002-2071-3724\")),\nperson(\"Emir\", \"Karayağız\", role = \"aut\",\ncomment = c(ORCID = \"0009-0005-1673-621X\")),\nperson(\"The authors of the dependency Rust crates\", role = \"ctb\",\ncomment = \"see inst/AUTHORS file for details\"))", "Description": "Build and run metaheuristic optimization algorithms as\nserializable component graphs executed by a 'Rust' core, with\nreproducible, bit-exact trajectories shared across the 'R' and\n'Python' frontends. Includes population and local-search\nalgorithm presets, standard benchmark suites (BBOB, CEC\n2014/2017/2022, TSP), multi-objective indicators,\nstructural-bias diagnostics and statistical comparison tools.", "License": "MIT + file LICENSE", "Copyright": "sezgi authors, except as documented in inst/COPYRIGHTS\n(bundled benchmark data and quoted reference excerpts)", "Encoding": "UTF-8", "SystemRequirements": "Cargo (Rust's package manager), rustc (>= 1.88)", "URL": "https://github.com/tdelphi1981/sezgi", "BugReports": "https://github.com/tdelphi1981/sezgi/issues", "Config/testthat/edition": "3", "Config/roxygen2/version": "8.1.0", "Config/sezgi/MSRV": "1.88.0", "Config/pak/sysreqs": "libclang-dev", "Repository": "https://tdelphi1981.r-universe.dev", "Date/Publication": "2026-10-03 21:22:14 UTC", "RemoteUrl": "https://github.com/tdelphi1981/sezgi", "RemoteRef": "HEAD", "RemoteSha": "4868fb10b945a58de0b8a3c8aef3055204193887", "RemoteSubdir": "r-sezgi", "NeedsCompilation": "yes", "Packaged": { "Date": "2026-10-03 21:34:28 UTC", "User": "root" }, "Author": "Tolga Berber [aut, cre] (ORCID:\n),\nBeyzanur Siyah [aut] (ORCID: ),\nEmir Karayağız [aut] (ORCID: ),\nThe authors of the dependency Rust crates [ctb] (see inst/AUTHORS file\nfor details)", "Maintainer": "Tolga Berber ", "_user": "tdelphi1981", "_type": "src", "_file": "sezgi_0.1.6.tar.gz", "_fileid": "https://r2.ropensci.org/d1c5e685b2219d715bb1aff01bbf33799c76705c17da86148949b62bd36dd0c9", "_filesize": 2710832, "_sha256": "d1c5e685b2219d715bb1aff01bbf33799c76705c17da86148949b62bd36dd0c9", "_expires": "2027-01-11T21:41:25.000Z", "_created": "2026-10-03T21:34:28.000Z", "_published": "2026-10-03T21:41:27.074Z", "_jobs": [ { "job": 111298368197, "time": 176, "config": "linux-devel-arm64", "r": "4.7.0", "check": "OK", "artifact": "11286011468" }, { "job": 111298368324, "time": 190, "config": "linux-devel-x86_64", "r": "4.7.0", "check": "OK", "artifact": "11286350655" }, { "job": 111298368256, "time": 135, "config": "linux-release-arm64", "r": "4.6.1", "check": "OK", "artifact": "11285676403" }, { "job": 111298368174, "time": 179, "config": "linux-release-x86_64", "r": "4.6.1", "check": "OK", "artifact": "11286325715" }, { "job": 111298368233, "time": 153, "config": "macos-oldrel-arm64", "r": "4.5.3", "check": "OK", "artifact": "11285318567" }, { "job": 111298368176, "time": 269, "config": "macos-oldrel-x86_64", "r": "4.5.3", "check": "OK", "artifact": "11285801204" }, { "job": 111298368177, "time": 119, "config": "macos-release-arm64", "r": "4.6.1", "check": "OK", "artifact": "11286305705" }, { "job": 111298368120, "time": 325, "config": "macos-release-x86_64", "r": "4.6.1", "check": "OK", "artifact": "11285497040" }, { "job": 111297431944, "time": 320, "config": "source", "r": "4.6.1", "check": "OK", "artifact": "11286081039" }, { "job": 111298368074, "time": 176, "config": "wasm-release", "r": "4.6.0", "check": "OK", "artifact": "11285396913" }, { "job": 111298368186, "time": 301, "config": "windows-devel-arm64", "r": "4.7.0", "check": "OK", "artifact": "11285481970" }, { "job": 111298368151, "time": 261, "config": "windows-devel-x86_64", "r": "4.7.0", "check": "OK", "artifact": "11285951723" }, { "job": 111298368269, "time": 242, "config": "windows-oldrel-x86_64", "r": "4.5.3", "check": "OK", "artifact": "11286156216" }, { "job": 111298368255, "time": 318, "config": "windows-release-arm64", "r": "4.6.1", "check": "OK", "artifact": "11285706383" }, { "job": 111298368221, "time": 226, "config": "windows-release-x86_64", "r": "4.6.1", "check": "OK", "artifact": "11285956599" } ], "_host": "GitHub-Actions", "_buildurl": "https://github.com/r-universe/tdelphi1981/actions/runs/37155303588", "_status": "success", "_upstream": "https://github.com/tdelphi1981/sezgi", "_commit": { "id": "4868fb10b945a58de0b8a3c8aef3055204193887", "author": "TURKCELL\\EXT02D20661 ", "committer": "TURKCELL\\EXT02D20661 ", "message": "Merge generator-owned-state-016: pso/jde/mfo generator-owned state and hybrid dispatch (0.1.6)\n", "time": 1791062534 }, "_maintainer": { "name": "Tolga Berber", "email": "tolga.berber@fen.ktu.edu.tr", "login": "tdelphi1981", "description": "", "uuid": 10599801, "orcid": "0000-0002-6487-5581" }, "_distro": "resolute", "_registered": true, "_dependencies": [ { "package": "R", "version": ">= 4.2", "role": "Depends" }, { "package": "R6", "version": ">= 2.4.0", "role": "Imports" }, { "package": "testthat", "version": ">= 3.0.0", "role": "Suggests" }, { "package": "jsonlite", "role": "Suggests" } ], "_owner": "tdelphi1981", "_selfowned": true, "_usedby": 0, "_updates": [ { "week": "2026-35", "n": 70 }, { "week": "2026-36", "n": 20 }, { "week": "2026-40", "n": 9 } ], "_tags": [ { "name": "v0.1.0", "date": "2026-09-04" }, { "name": "v0.1.1", "date": "2026-09-05" }, { "name": "v0.1.2", "date": "2026-10-02" }, { "name": "v0.1.3", "date": "2026-10-03" }, { "name": "v0.1.4", "date": "2026-10-03" }, { "name": "v0.1.5", "date": "2026-10-03" }, { "name": "v0.1.6", "date": "2026-10-03" } ], "_stars": 0, "_userbio": { "uuid": 10599801, "type": "user", "name": "Tolga BERBER", "followers": 21 }, "_downloads": { "count": 269, "source": "https://cranlogs.r-pkg.org/downloads/total/last-month/sezgi" }, "_devurl": "https://github.com/tdelphi1981/sezgi", "_searchresults": 35, "_cargo": true, "_topics": [ "rust", "cargo" ], "_rbuild": "4.6.1", "_assets": [ "extra/citation.cff", "extra/citation.html", "extra/citation.json", "extra/citation.txt", "extra/contents.json", "extra/manual.pdf", "extra/NEWS.html", "extra/NEWS.txt", "extra/readme.html", "extra/readme.md", "extra/sezgi.html", "LICENSE" ], "_realowner": "tdelphi1981", "_cranurl": false, "_releases": [ { "version": "0.1.1", "date": "2026-09-15" } ], "_exports": [ "Algorithm", "AntLion", "ArtificialBeeColony", "BatAlgorithm", "CMAES", "CMAESIpop", "CuckooSearch", "DifferentialEvolution", "EvolutionStrategy", "FeatureSelection", "FireflyAlgorithm", "FlowerPollination", "GeneticAlgorithm", "GrasshopperOptimization", "GravitationalSearch", "GreyWolfOptimizer", "HarmonySearch", "HarrisHawks", "JAYA", "LocalSearch", "LSHADE", "MixedTuning", "MothFlameOptimization", "NelderMead", "NSGA2", "ParticleSwarm", "PopulationAlgorithm", "Problem", "RandomSearch", "SalpSwarm", "sezgi_version", "SHADE", "SimulatedAnnealing", "SineCosineAlgorithm", "sz_algo_solve", "sz_algorithm", "sz_as_problem", "sz_bayesian_plackett_luce", "sz_bias_central", "sz_bias_report", "sz_bias_structural", "sz_bias_structural_positions", "sz_binary", "sz_builtin_bbob", "sz_categorical", "sz_cec2014_evaluate", "sz_cec2014_f_star", "sz_cec2017_evaluate", "sz_cec2017_f_star", "sz_cec2022_evaluate", "sz_cec2022_f_star", "sz_coco_export", "sz_ecdf", "sz_eval_session", "sz_eval_session_cec2014", "sz_eval_session_cec2017", "sz_eval_session_cec2022", "sz_eval_session_f0", "sz_eval_session_tsp", "sz_float", "sz_int", "sz_mo_evaluate", "sz_mo_evaluate_constraints", "sz_mo_hypervolume", "sz_mo_hypervolume_2d", "sz_mo_igd", "sz_mo_pareto_front", "sz_mo_read_moa", "sz_nsga2", "sz_per_budget_packages", "sz_permutation", "sz_preset_abc", "sz_preset_alo", "sz_preset_bat", "sz_preset_cmaes", "sz_preset_cmaes_ipop", "sz_preset_cuckoo_search", "sz_preset_de_best_1", "sz_preset_de_rand_1", "sz_preset_es_mu_plus_lambda", "sz_preset_firefly", "sz_preset_fpa", "sz_preset_ga_bin", "sz_preset_ga_cat", "sz_preset_ga_int", "sz_preset_ga_perm", "sz_preset_ga_real", "sz_preset_goa", "sz_preset_gsa", "sz_preset_gwo", "sz_preset_harmony_search", "sz_preset_hho", "sz_preset_jaya", "sz_preset_jde", "sz_preset_lshade", "sz_preset_mfo", "sz_preset_nelder_mead", "sz_preset_pso", "sz_preset_random_search", "sz_preset_sa", "sz_preset_sca", "sz_preset_shade", "sz_preset_ssa", "sz_preset_tlbo", "sz_preset_woa", "sz_read_ioh_records", "sz_results_matrix", "sz_run_experiment", "sz_solve_bbob", "sz_solve_cat_match", "sz_solve_cec2014", "sz_solve_cec2017", "sz_solve_cec2022", "sz_solve_int_quadratic", "sz_solve_mixed_diagnostic", "sz_solve_onemax", "sz_solve_tsp", "sz_space", "sz_stats_bayesian_signed_rank", "sz_stats_cliffs_delta", "sz_stats_cliffs_magnitude", "sz_stats_friedman", "sz_stats_paper_package", "sz_stats_plackett_luce", "sz_stats_wilcoxon", "sz_tsp_load", "sz_tsp_tour_length", "TLBO", "WhaleOptimization" ], "_help": [ { "page": "Algorithm", "title": "Subclassable R6 base for an engine-hosted algorithm.", "topics": [ "Algorithm" ] }, { "page": "DifferentialEvolution", "title": "Differential Evolution - delegates to `sz_preset_de_rand_1` (default, DE/rand/1/bin), `sz_preset_de_best_1` (DE/best/1/bin), or `sz_preset_jde` (self-adaptive jDE), selected by `variant` (one of `\"rand_1\"`, `\"best_1\"`, `\"jde\"`) at `$new()` time. All three presets share the identical `(pop_size, budget)` signature, so `variant` is the only dispatch axis - no problem introspection needed (unlike [GeneticAlgorithm]'s space-driven auto-dispatch).", "topics": [ "DifferentialEvolution" ] }, { "page": "EvalSession", "title": "The ask/tell evaluation session - see the module doc.", "topics": [ "EvalSession" ] }, { "page": "FeatureSelection", "title": "Binary feature-selection search over a 2D dataset's columns.", "topics": [ "FeatureSelection" ] }, { "page": "GeneticAlgorithm", "title": "Genetic Algorithm - auto-dispatches to `sz_preset_ga_real`/`ga_perm`/ `ga_bin`/`ga_int`/`ga_cat` (`R/000-wrappers.R`) based on `problem`'s own search space, read via `prob$space()`/`.sz_space_to_blocks()`:", "topics": [ "GeneticAlgorithm" ] }, { "page": "LocalSearch", "title": "Family base for single-trajectory local search (hill-climbing/ SA-shaped).", "topics": [ "LocalSearch" ] }, { "page": "MixedTuning", "title": "The general \"tune anything\" door: binds a caller-supplied `objective(x) -> numeric(1)` over ANY declared `sz_space(...)` - a single block (`sz_float(...)`, `sz_categorical(...)`, ...) or a multi-block space. `evaluate(x)` delegates to `objective` UNCHANGED - `x`'s exact shape follows [Problem]'s own genotype conversion table (a bare converted value for a single-block space, an unnamed `list` of per-block converted values in `space()`'s own block order for a multi-block one).", "topics": [ "MixedTuning" ] }, { "page": "NSGA2", "title": "Class skin over [sz_nsga2()] (`R/mo.R`) - NOT one of the 34 `sz_preset_*` builders (NSGA-II is not built on the scalar Engine/Registry/Generator/AlgorithmSpec machinery every `sz_preset_*` targets, see this file's own module doc). ZERO new MO capability: `$run()` delegates to `sz_nsga2()` VERBATIM, same positional/keyword arguments, same return value shape.", "topics": [ "NSGA2" ] }, { "page": "PopulationAlgorithm", "title": "Family base for population-style algorithms (GA/DE/ES-shaped).", "topics": [ "PopulationAlgorithm" ] }, { "page": "print.sz_block", "title": "Prints an `sz_block` object (any of the five block kinds).", "topics": [ "print.sz_block" ] }, { "page": "print.sz_result", "title": "Prints an `sz_result` object.", "topics": [ "print.sz_result" ] }, { "page": "print.sz_space", "title": "Prints an `sz_space` object.", "topics": [ "print.sz_space" ] }, { "page": "Problem", "title": "Subclassable R6 base for a search-space problem.", "topics": [ "Problem" ] }, { "page": "sezgi_version", "title": "Version of the underlying sezgi Rust core.", "topics": [ "sezgi_version" ] }, { "page": "sz_algo_solve", "title": "Drives an `sz_algorithm` over an `EvalSession` to exhaustion.", "topics": [ "sz_algo_solve" ] }, { "page": "sz_algorithm", "title": "Declares a pure-R metaheuristic algorithm to run over an `EvalSession`.", "topics": [ "sz_algorithm" ] }, { "page": "sz_as_problem", "title": "Accepts a `Problem` subclass instance.", "topics": [ "sz_as_problem" ] }, { "page": "sz_bayesian_plackett_luce", "title": "Bayesian Plackett-Luce posterior via Gibbs sampling.", "topics": [ "sz_bayesian_plackett_luce" ] }, { "page": "sz_bias_central", "title": "Central-bias scan: run an algorithm spec on paired centered/shifted BBOB conditions and test whether its performance gap differs between them (Kudela's center-bias-exploitation method). See `crates/bias/src/central.rs` for the full method provenance.", "topics": [ "sz_bias_central" ] }, { "page": "sz_bias_report", "title": "One-call bias report: runs both the structural and central bias scans on one algorithm spec and assembles a single report with a ready-to-paste LaTeX summary table. See `crates/bias/src/report.rs` for the full assembly/LaTeX-rendering details.", "topics": [ "sz_bias_report" ] }, { "page": "sz_bias_structural", "title": "Structural-bias scan: run an algorithm spec repeatedly on the f0 random-function null problem and test its final positions for departure from uniformity (BIAS-toolbox method; Kononova et al. 2015 / Vermetten et al. 2022). See `crates/bias/src/structural.rs` for the full method provenance.", "topics": [ "sz_bias_structural" ] }, { "page": "sz_bias_structural_positions", "title": "Statistics-only structural-bias scan over externally-collected final positions - the bias bridge for algorithms authored OUTSIDE this package's own spec/engine (M3-5 Task 6), e.g. a pure-R 'sz_algorithm' driven by 'sz_algo_solve' over 'sz_eval_session_f0', one run at a time. Runs the SAME KS/AD/ Holm battery as 'sz_bias_structural' over caller-supplied `final_positions` instead of driving an algorithm spec through the engine itself - see 'crates/bias/src/structural.rs''s `scan_from_positions` for the full method provenance. Mirrors py-sezgi's `sezgi.bias.structural_positions()` 1:1.", "topics": [ "sz_bias_structural_positions" ] }, { "page": "sz_binary", "title": "A binary block: `n` bits.", "topics": [ "sz_binary" ] }, { "page": "sz_builtin_bbob", "title": "A built-in-problem descriptor for [Algorithm]'s `run()`.", "topics": [ "sz_builtin_bbob" ] }, { "page": "sz_categorical", "title": "A categorical block: `n` genes, each a category index in `0..k`.", "topics": [ "sz_categorical" ] }, { "page": "sz_cec2014_evaluate", "title": "Direct, one-shot evaluation of a CEC 2014 (Liang, Qu & Suganthan 2013) function at `x`, bypassing `sz_solve_bbob`-style budget/engine machinery entirely - binds [`Cec2014::new`] + [`Cec2014::evaluate_batch`] exactly. Mirrors `sz_cec2022_evaluate` (M3-6 Task 10 - see py-sezgi's `sezgi.problems.cec2014_evaluate` for the identical binding on the Python side). See [`Cec2014::new`]'s own doc for the exact `fid`/`dim` domain.", "topics": [ "sz_cec2014_evaluate" ] }, { "page": "sz_cec2014_f_star", "title": "The report's pinned `F_i*` bias for a CEC 2014 function - binds [`Cec2014::f_star`] (`F_i* = 100*fid`). Does not depend on `dim`, so an internal probe `dim = 10` is used purely to validate `fid`.", "topics": [ "sz_cec2014_f_star" ] }, { "page": "sz_cec2017_evaluate", "title": "Direct, one-shot evaluation of a CEC 2017 (Awad, Ali, Liang, Qu & Suganthan 2016) function at `x`, bypassing `sz_solve_bbob`-style budget/engine machinery entirely - binds [`Cec2017::new`] + [`Cec2017::evaluate_batch`] exactly. Mirrors `sz_cec2014_evaluate` (M3-6 Task 10 - see py-sezgi's `sezgi.problems.cec2017_evaluate` for the identical binding on the Python side). See [`Cec2017::new`]'s own doc for the exact `fid`/`dim` domain.", "topics": [ "sz_cec2017_evaluate" ] }, { "page": "sz_cec2017_f_star", "title": "The report's pinned `F_i*` bias for a CEC 2017 function - binds [`Cec2017::f_star`] (`F_i* = 100*fid`, the fid-gapped C dispatch bias, not the report's contiguous renumbering - see `Cec2017::new`'s own module doc). Does not depend on `dim`, so an internal probe `dim = 10` is used purely to validate `fid`.", "topics": [ "sz_cec2017_f_star" ] }, { "page": "sz_cec2022_evaluate", "title": "Direct, one-shot evaluation of a CEC 2022 function at `x`, bypassing `sz_solve_bbob`-style budget/engine machinery entirely - binds [`Cec2022::new`] + [`Cec2022::evaluate_batch`] exactly. See `Cec2022::new`'s own doc for the exact `fid`/`dim` domain.", "topics": [ "sz_cec2022_evaluate" ] }, { "page": "sz_cec2022_f_star", "title": "The report's pinned `F_i*` bias for a CEC 2022 function - binds [`Cec2022::f_star`] (module doc section 1.2's table). `f_star` does not depend on `dim`, so an internal probe `dim = 10` is used purely to validate `fid` (every `fid` in `1..=12` accepts `dim = 10`, hybrids included).", "topics": [ "sz_cec2022_f_star" ] }, { "page": "sz_coco_export", "title": "Exports the IOH archive at `log_root` as a COCO/BBOB \"old format\" archive rooted at `out_dir` - see `sezgi_bench::coco_export`. Returns the list of written file paths (as strings), sorted for determinism.", "topics": [ "sz_coco_export" ] }, { "page": "sz_ecdf", "title": "ECDF/anytime curve(s) over an on-disk IOH archive.", "topics": [ "sz_ecdf" ] }, { "page": "sz_eval_session", "title": "Start an ask/tell evaluation session over a BBOB problem.", "topics": [ "sz_eval_session" ] }, { "page": "sz_eval_session_cec2014", "title": "Start an ask/tell evaluation session over a CEC 2014 problem.", "topics": [ "sz_eval_session_cec2014" ] }, { "page": "sz_eval_session_cec2017", "title": "Start an ask/tell evaluation session over a CEC 2017 problem.", "topics": [ "sz_eval_session_cec2017" ] }, { "page": "sz_eval_session_cec2022", "title": "Start an ask/tell evaluation session over a CEC 2022 problem.", "topics": [ "sz_eval_session_cec2022" ] }, { "page": "sz_eval_session_f0", "title": "Start an ask/tell evaluation session over the f0 BIAS-toolbox null problem.", "topics": [ "sz_eval_session_f0" ] }, { "page": "sz_eval_session_tsp", "title": "Start an ask/tell evaluation session over a vendored TSPLIB (TSP) instance.", "topics": [ "sz_eval_session_tsp" ] }, { "page": "sz_float", "title": "A continuous block: `n` coordinates, each in `[lo, hi]`.", "topics": [ "sz_float" ] }, { "page": "sz_int", "title": "An integer block: `n` coordinates, each in `[lo, hi]` (inclusive).", "topics": [ "sz_int" ] }, { "page": "sz_mo_evaluate", "title": "Direct, one-shot objective evaluation of a decision vector `x` against any `sz_mo_*` problem string, bypassing `sz_nsga2()`'s population/budget machinery entirely. Added (M3-7) so fixture-value tests can pin an exact `x` (`sz_nsga2()`'s randomly-initialized population cannot), mirroring the existing `sz_cec2022_evaluate()`/`sz_cec2014_evaluate()`/ `sz_cec2017_evaluate()` one-shot-evaluation convention.", "topics": [ "sz_mo_evaluate" ] }, { "page": "sz_mo_evaluate_constraints", "title": "The matching one-shot constraint-row evaluation for `sz_mo_evaluate()`, same calling convention.", "topics": [ "sz_mo_evaluate_constraints" ] }, { "page": "sz_mo_hypervolume", "title": "General-M exact hypervolume (While, Bradstreet & Barone 2012, the WFG algorithm; `M == 2` delegates internally to the SAME [`sezgi_stats::hypervolume_2d`]) - binds [`sezgi_stats::hypervolume`] (M3-7 Task 8/11). Unlike `sz_mo_hypervolume_2d`, `front`/`ref_point` may have any number `M >= 1` of objectives.", "topics": [ "sz_mo_hypervolume" ] }, { "page": "sz_mo_hypervolume_2d", "title": "Exact 2-objective hypervolume (Zitzler & Thiele 1999 S-metric, reference-point variant; minimization) - binds [`sezgi_stats::hypervolume_2d`] exactly. See that function's doc for the pinned definition.", "topics": [ "sz_mo_hypervolume_2d" ] }, { "page": "sz_mo_igd", "title": "Inverted Generational Distance (Ishibuchi et al. 2015, eq. 12, `p = 1`) - binds [`sezgi_stats::igd`] exactly. Any (equal, consistent) number of objectives across both `front` and `reference_front`.", "topics": [ "sz_mo_igd" ] }, { "page": "sz_mo_pareto_front", "title": "A deterministic `n`-point sample of the analytic Pareto front in OBJECTIVE space, if known. See `MoProblem::pareto_front` in `crates/core/src/mo.rs`.", "topics": [ "sz_mo_pareto_front" ] }, { "page": "sz_mo_read_moa", "title": "Reads a \"sezgi-moa v1\" archive file written by `sz_nsga2(..., log_dir =, label =)` (M3-7 Task 9/11) - binds [`sezgi_bench::read_moa`]. Returns a named list: - `algo` (character): the logging algorithm name - always `\"nsga2\"` today (`nsga2_run_logged`'s own fixed `NSGA2_ALGO_NAME`). - `problem` (character): the `label` `sz_nsga2` was called with. **Kept as the literal on-disk header key name** (`crates/bench/src/mo_archive.rs`'s own format grammar: the header line is `problem