deterministic OCaml engine to compute and validate liturgical calendars for multiple rites, template-driven output to year 9999 https://git.labunix.xyz/colitur.git/atom?h=v0.10.1 2026-08-21T13:12:08Z 2026-08-21T13:12:08Z Lukasz Kasprzak lukas@labunix.xyz 2026-08-21T13:12:08Z urn:sha1:d129b9b9a766c3530d2dd6ac131ebafd1bddf7a5 The Latin Mass Society Ordo 2024-2025 for England and Wales (v2.21, compiled by Peter Day-Milne) gives 9 August 2025 as "OUR LADY on SATURDAY IV Cl W / V Mass of BVM / Commem of St Romanus M at Low Mass" -- no vigil -- and 10 August as the 9th Sunday after Pentecost with St Laurence commemorated. That is colitur's output on both days, field for field. It is discriminating where the Ordo already in docs/research was not. This edition lists six vigils as the day's office across its year, including the Assumption's on 14 August 2025, and its footnotes discuss arranging a diocesan feast around the Vigil of St Laurence in other years. Its absence on 9 August 2025 is an application of the rule, not a data gap. The extraordinaryform.org Ordo omits that vigil on every date it covers, including 2027-08-09 where the clause says to keep it, which is why it witnesses nothing here. Also confirms the Vigil of the Assumption as II Cl violet, the RG 128 colour this project corrected from the bootstrap's White. The clause's other shape -- feast transferred away, 2022/2033/2038/2044 -- remains unwitnessed; no accessible Ordo covers those years. Stated in the note rather than left implied. 2026-08-21T13:04:52Z Lukasz Kasprzak lukas@labunix.xyz 2026-08-21T13:04:52Z urn:sha1:f3ac69d0a679200a48716be065a0fa2e70a2c6da Replaces the withdrawn Ordo claim with a real one of a different kind. O'Connell, The Celebration of Mass (4th ed., 1964) -- a rubrics commentary contemporary with the 1960 Code, outside the Divinum Officium -> missalemeum -> lectio lineage, already cited here for RG 128 -- states all three of RG 33's triggers in English, the third included, verbatim in substance with the Latin. The same passage confirms vigil_feast_table's membership independently: Christmas Eve and Pentecost I class and so outside the rule; Ascension, Assumption, John the Baptist and Peter & Paul II class; St Lawrence the sole III-class vigil. Five entries, the same five, same class split. It confirms the RULE and the ENTITY LIST, not the 10 days -- O'Connell publishes no day-by-day calendar. The distinction is stated in the note rather than blurred, since blurring it is what the withdrawn Ordo paragraph did. 2026-08-21T13:00:03Z Lukasz Kasprzak lukas@labunix.xyz 2026-08-21T13:00:03Z urn:sha1:afd82f97ff440add51ea3e87c7ab53938443d5a0 C39 and the 2025 golden pin both claimed the published Ordo independently confirms RG 33's third trigger, because it omits St Lawrence's vigil on 2025-08-09 where lectio and missalemeum keep it. It does not. The Ordo omits that vigil on 2027-08-09 as well, where the clause says to keep it (10 August is a Tuesday, the feast holds its day), and 2026-08-09 is a Sunday where the rule's first trigger omits it anyway. The 2024 date has no row. So the Ordo never shows St Lawrence's vigil on any date it covers, and the 2025 agreement is a blanket gap coinciding with the right answer, not evidence. The rule itself is unaffected: it rests on RG 33's text, which admits no latitude, and on lectio not evaluating the clause at all -- "RG 33" appears nowhere in its production code, and the third trigger cannot emerge from per-day rank comparison because it turns on what is observed the following day. The divergence is architectural, not a disagreement about the rubric. Recorded rather than deleted: the withdrawn claim is why this entry was first written up as unusually well corroborated. 2026-08-21T12:46:34Z Lukasz Kasprzak lukas@labunix.xyz 2026-08-21T12:46:34Z urn:sha1:8072287da9d8e8a9e2de8b7845923f5d576dea55 The note apportioned the entry's ten rows as seven commemoration-reduced and three transferred, counting 2038-06-23 in both halves to make the arithmetic work. It is six and four; the row count itself was always right, and is pinned by the comparator. 2026-08-21T12:42:30Z Lukasz Kasprzak lukas@labunix.xyz 2026-08-21T12:42:30Z urn:sha1:12b97761019cfa02ca0da8a5fb50ef815d07685c RG 33 omits a II/III-class vigil in three cases: it falls on a Sunday, it falls on a I-class feast, "vel si festum cui praemittitur in alium diem transferri aut ad commemorationem reduci contingat". Only the first two were built; the third was recorded in precedence_ef.ml as unimplemented on the grounds that no witness existed in the shipped data. That reasoning was wrong, and the rule fires on 1 744 days across 1583-9999. Both halves of the clause reduce to one observable question -- is the feast the OBSERVED office on the following day (RG 34 puts it there) -- so the kernel asks it once per candidate, after place_transfers has settled the year. No fixed point is needed: a vigil is a candidate only on its own day, never on its feast's, so suppressing it cannot change what the next day observes. Precedence.rules gains vigil_feast, which returns the slug of the feast a vigil precedes; the kernel cannot infer that itself, because only two of the five vigil/feast pairs share a slug stem. Blast radius, measured pre-change binary vs HEAD over the whole domain and classified: 1 744 days, three shapes, zero unexplained. 1 199 are the feast reduced to a commemoration (10 August on a Sunday, St Lawrence); 478 and 67 are the feast transferred under RG 96 after the Sacred Heart or Corpus Christi takes its day. The Assumption's and the Ascension's vigils never qualify -- their I-class feasts always keep their own day. Independently witnessed, which is unusual here. The published Ordo -- the only witness outside the Divinum Officium -> missalemeum -> lectio lineage -- omits St Lawrence's vigil on 2025-08-09, agreeing with colitur against both engines. That date had been read earlier as an Ordo gap; the Ordo was right, and correcting the misreading is what surfaced this clause. On 2027-08-09 the feast does keep its day and the Ordo omits a vigil colitur correctly keeps, which is a genuine Ordo gap. Allow-lists: C39 (lectio, 10 rows) and a 2038 oracle class citing the register, the 2026-2027 window having no instance. The golden pin asserting St Lawrence's vigil is violet moved 2025 -> 2027; its own comment had reasoned about the vigil's weekday and missed that RG 33 also looks at the feast's. Two new pins cover both shapes of the clause. The vigil/feast table is built with Slug.of_string_exn: mutation testing showed that of_string plus Result.to_option turns a typo into None, which this hook's contract reads as "not a vigil", switching the rule off in silence. Two tests assert the table against the shipped data in both directions. 2026-08-18T15:35:53Z Lukasz Kasprzak lukas@labunix.xyz 2026-08-18T15:35:53Z urn:sha1:897c274fd28402159ca6d45eedc1257b1ce98696 lectio adopted the last two Missal corrections colitur argued: C14 3 -> 0 RG 96(a)/97/98. lectio resolved each impeded I-class feast's transfer independently, so in 2008, 2035 and 2046 St Joseph and the Annunciation both walked onto the Monday after Low Sunday and Joseph, losing there, was observed on no day of those years at all. It now resolves the year's transfers as a set: the Annunciation takes the Monday as its sedes propria, Joseph the Tuesday. C15 7 -> 0 The Holy Family propers' own 13-January rubric, "sine commemoratione Baptismatis D.N.I.C.". lectio kept the Baptism as the observed office on all seven such years in 2005-2050. Those were the last two BEHAVIOUR classes. What is left is C1 (138) and C6 (119), both pure slug vocabulary. Measured across the whole fixture, applying only the season normalisation the test already applies: 579 of 16801 days differ, and every one of them differs on the SLUG ALONE. Zero days differ on season, rank, colour, Epistle or Gospel. (The test's own norm_slug table already maps 322 of the 579; the 257 left are C1 and C6. The field profile is the same either way.) So the two engines now agree on every liturgically meaningful field on every day of 2005-2050. The residue is what the two projects call things -- ef-christmas-2-friday against ef-time-after-epiphany-1-friday for the same day, same Mass. Aligning it means renaming lectio's slugs, and those are keys: its lectionary, clectio's generated tables and any user overlay are built on them. Left as vocabulary rather than forced. Fixture refreshed against lectio e713da2; 13 rows changed, colitur agrees with all of them. 24 divergence classes at the start of this work, 2 now. 2026-08-18T15:18:16Z Lukasz Kasprzak lukas@labunix.xyz 2026-08-18T15:18:16Z urn:sha1:5773d603a2936638654f8e6bd8e595240de4203a The ferias between Epiphany and the first Sunday after it repeat Epiphany's own Mass in lectio now; they had been taking the Mass of the Sunday that follows them. C31 98 -> 0 C1 40 -> 138 grew, and changed character C1 is now SLUG VOCABULARY ONLY, and its note says so. Season, rank, colour and both citations agree with colitur on every day of the January window; what differs is the identifier -- ef-christmas-2-thursday against ef-time-after-epiphany-1-thursday for the same day with the same Mass. C6 is the same shape. That is 257 of the 267 remaining rows. Aligning the vocabularies would mean renaming lectio's slugs, and those are keys: its own lectionary, clectio's generated tables and any user overlay are built on them. Recorded as vocabulary rather than closed, because the rows do differ -- just not in anything a reader of either engine's output sees. Measured for 2026: season, rank and colour agree on all 365 days; 14 days differ and every one differs on the slug alone. 5 classes -> 4, agreement 98.4%. 2026-08-18T15:13:03Z Lukasz Kasprzak lukas@labunix.xyz 2026-08-18T15:13:03Z urn:sha1:60db67eb2246d748d1e8e55047cef7d3d7843c4e lectio carries the readings of the nine Common-routed saints and of three more that had proper Masses but no reading at all. Every day of 2005-2050 now resolves a reading there; four days used to come back empty. C38's own note said it could not close without lectio gaining a Commons concept. The readings arrived instead of the abstraction, which was enough: each Common resolves to one first/gospel pair for the saint that names it, so a table plus assignment layer would have bought indirection and nothing else. C20 14 -> 0 C38 70 -> 0 7 classes -> 5, 351 rows -> 267, agreement 97.9% -> 98.4%. 2026-08-18T14:51:45Z Lukasz Kasprzak lukas@labunix.xyz 2026-08-18T14:51:45Z urn:sha1:3c770951011d2fd4911cd98793683bef69ac2d27 lectio gained the Passiontide week split and thirteen lectionary entries. C23 230 -> 0 Holy Week's own six Masses C32 99 -> 0 C35 60 -> 0 the first weeks after Epiphany and Pentecost (RG 299) C33 46 -> 0 Corpus Christi C34 46 -> 0 the Sacred Heart C26 43 -> 0 Passion Tuesday C19 7 -> 0 the Holy Family week-index residue C1 75 -> 40 C31 63 -> 98 GREW The Passiontide split is the one that carried most of this. efWeek had no Passiontide case, so both weeks numbered 0 and every day of Holy Week took the slug of its Passion-week namesake -- one set of readings for two weeks with entirely different Masses. Good Friday was reading Passion Friday's. C31 growing is the same bookkeeping as C1's earlier growth and is recorded in its own note: C32 and C35 closed, and rows that carried several causes now carry only this one. Nothing new disagrees. 17 classes -> 10, 1019 rows -> 488, agreement 93.9% -> 97.1%. What remains is almost entirely NAMING rather than disagreement: C6 (119) is colitur's ef-nativity-octave-day-N against lectio's ef-christmas-N-weekday on days where both now read the same Mass, and C1 (40) is the same shape in the January window. 2026-08-18T14:38:15Z Lukasz Kasprzak lukas@labunix.xyz 2026-08-18T14:38:15Z urn:sha1:71054def597178f8143ed121e33460558456cce6 lectio gained Rogation Monday and Tuesday (RG 87, violet under RG 128(d)) and the Missal's own Mass for the weekdays within the Octave of the Nativity ("Diebus infra octavam Nativitatis Domini", Titus 3:4-7 / Luke 2:15-20). C8 26 -> 0 CLOSED C6 119 -> 119 narrowed: the cause halved, the count did not C6 is worth reading carefully rather than skimming the number. Its rows no longer differ on First_f or Gospel_f at all -- the two engines now read the SAME Mass on 29-31 December, where lectio previously served the Sunday's. What is left is Slug_f alone, colitur's ef-nativity-octave-day-N against lectio's ef-christmas-N-weekday. That is vocabulary, not disagreement. The count did not move because the entry's gate already admitted a Slug_f-only subset, which is exactly the case where a row count is a misleading summary. 17 classes, 1019 rows, agreement 93.9%.