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=v1.2.0 2026-08-22T18:55:18Z 2026-08-22T18:55:18Z Lukasz Kasprzak lukas@labunix.xyz 2026-08-22T18:55:18Z urn:sha1:9c96e0afc19925b651e0dfee3bc9182dee72acf0 Ascension has no octave under the 1960 rubrics -- confirmed structurally: the Proprium de Tempore's own table of contents runs straight from "In Ascensione Domini" to "Dominica post Ascensionem" with no per-feria headings in between. Step 3 of the reading chain therefore fell through to Preceding_sunday on every unoccupied weekday in that stretch, walking each one back to the 5th or 6th Sunday after Easter's own citation. The Missal's own Proprium de Tempore carries an explicit marginal rubric immediately after the Ascension's Mass propers, before "Dominica post Ascensionem" begins: "Diebus a feria VI post Ascensionem usque ad feriam VI ante vigiliam Pentecostes inclusive, dicitur Missa de festo Ascensionis, cum Gloria et praefatione de Ascensione, sine Credo et Communicantes proprio" -- every feria without its own proper, from the Friday after the Ascension through the Friday before the Vigil of Pentecost, repeats the Ascension's own Mass. RG 490(b) corroborates independently: it assigns the Ascension preface "tamquam de Tempore" across that identical window, which only makes sense if the Mass actually repeated there is the Ascension's, not a numbered Sunday's (whose own Mass would carry no need for a preface override at all). Witnessed directly, not only inferred from the rubric: the LMS Ordo prints "Mass of the Ascension" literally on every affected day across all three of its fixture windows, in BOTH the tail of Ascension's own week and the following week -- ruling out the alternative reading (that the second week instead resumes "Dominica post Ascensionem"'s own Mass, which a first pass over the FIUV Ordo's own week-labelled titles could suggest at a glance; its own [praef] field for the same two dates independently reads "Ascensionis", resolving the apparent conflict). Implemented as data, not logic, matching this codebase's own established precedent for the identical RG 299 shape (the week after Trinity Sunday, data/ef/lectionary.sexp's [trinity_week_entries]): six new hand-authored entries, [ascension_week_entries] in tools/bootstrap_lectionary.ml, regenerated against a git-pinned copy of lectio's own source ini (SHA-256 verified unchanged) so the regeneration carries no unrelated drift. The window's two Saturdays are deliberately excluded -- RG 78's votive Office of Our Lady on Saturday always wins an otherwise-unoccupied Class4 Saturday first, before step 2 (this fix's own entry point) is ever reached, so an entry for either slug would be dead data. Blast radius measured in-process across the full 1583-9999 domain (throwaway probe, not committed): 16 350 days total across the six slugs, every one resolved via step 2 (Own_slug), zero anomalies, and the window's two Saturdays confirmed to contribute zero hits via this cause across the whole domain, corroborating the RG78-interception reasoning by direct sweep. Closed L2 in data/ef/expected-divergences-lms.sexp. New cited entries: C41 in data/ef/expected-divergences.sexp (95 of 16801 rows, 2005-2050 -- lectio has no equivalent rubric and still walks these ferias back); M31 in data/ef/expected-divergences-missalemeum.sexp (3 rows in the 2026-2027 window, plus the same shape independently reconfirmed in the 2035 and 2038 live-capture windows) -- missalemeum, Divinum Officium's lineage, still gives the same wrong answer colitur itself used to give, which is why these rows used to agree with M18's shape and now escape it (M18 373 -> 370, the same mechanism M23-M27 established when the citation axis was first built). Golden pin: 2031-05-23, the exact date the bug report was filed against. Mutation-tested: reverting data/ef/lectionary.sexp alone (a git-diff capture/restore, not a source-code revert, since the fix is data) reddens 19 tests across the differential, both oracle fixtures, all three LMS Ordo windows, the golden pin, the lectionary unit test and every Render golden template; restored and reconfirmed green (681 tests; 683 under COLITUR_EXHAUSTIVE_SWEEP=1, ~175s). 2026-08-22T18:15:56Z Lukasz Kasprzak lukas@labunix.xyz 2026-08-22T18:15:56Z urn:sha1:cd3e03bf3e5b040786838fc3c5639d7c29e9b3b8 Temporal_ef.temporal's Rogation Monday/Tuesday branch hardcoded Colour.Violet with no citation (data/ef/expected-divergences-lms.sexp's L6, surfaced by the LMS Ordo). RG 119 assigns white to the de-Tempore Office and Mass from the Paschal Vigil Mass to the Pentecost Vigil Mass exclusive; Easter+36/+37 sit inside that window. RG 128's own exhaustive four-case violet list never names Rogation days, and its vigil clause (d) is doubly inapplicable: these are not vigils, and they are inside Paschaltide, not outside it. RG 88 explains the violet actually seen in print sources: "de Litaniis minoribus nihil fit in Officio, sed tantum in Missa" -- the violet belongs to the Rogation Mass/procession, a distinct votive text this engine does not model, not to the day's own Office. Witnessed directly: LMS Ordo 2023-2024, 2024-05-06, "FERIA IV Cl W" with "Gl", the Office and Mass printed separately from the optional violet votive Mass of the Rogations. Cascade verified, not assumed: RG 432(b) omits the Gloria on every violet Mass, so the wrong colour was also silencing the Gloria on these two weekdays even though RG 237(e) (Breviary, ordinary Paschaltide ferias say Te Deum) already made it true underneath. White removes the 432(b) block, and the Gloria now follows Te Deum via 431(a), matching the Ordo's own "Gl" -- confirmed with dedicated golden pins in both test_golden.ml (colour) and test_rubrics_ef.ml (the Gloria flip), 2028-05-22/23 (neither day impeded that year). Closed L6 in data/ef/expected-divergences-lms.sexp. Reopened C8 in data/ef/expected-divergences.sexp (26 of 16801 rows, 2005-2050): lectio independently computes these two days violet too, so the two engines used to agree by sharing the same uncited assumption; colitur's colour is now correct and lectio's is not, so the comparator disagrees again, for the opposite reason. While reopening C8, found and corrected a genuine misattribution in its own prior closure note, which claimed lectio's violet was "RG 128(d)" -- 128(d) governs vigils outside Paschaltide and has nothing to do with Rogation days. Checked docs/research/rules-register.md for the same claim: not present there, but a related conflation was found and corrected at its O'Connell section 4(d) note, which had used a Rogation MASS/procession citation to "confirm" the day's own OFFICE colour. Blast radius measured in-process across the full 1583-9999 domain (throwaway probe, not committed): 4722 days total (2368 Rogation Mondays + 2354 Rogation Tuesdays actually observed outright, i.e. not impeded by a stronger sanctoral feast that year), all Violet->White, all with the Gloria flipping false->true alongside, zero anomalies. Mutation-tested: reverting the branch to Colour.Violet reddens 16 tests across Rubrics_ef, the lectio differential, the LMS Ordo suite and both golden pin files; restored and reconfirmed green (680 tests). 2026-08-22T14:40:24Z Lukasz Kasprzak lukas@labunix.xyz 2026-08-22T14:40:07Z urn:sha1:60e87914718dd2c8e69bb89d8cc48d6bef9bfc74 The Missale Romanum's calendarium footnote for February (LT.txt:5011-5014, scan-corroborated scan2.txt:3050-3058): in a leap year the sixth kalends of March (24 February) is doubled rather than a 29th day appended, so St Matthias moves 24->25 February and St Gabriel of Our Lady of Sorrows 27->28, with 24 February itself carrying no fixed office that year. data/ef/expected-divergences-lms.sexp entry L3 tracked this as an open gap. Implemented as the rubric's own general mechanism (every fixed entry from 24 through 28 February shifts one civil day later in a leap year), not as "move these two named saints": the two readings are indistinguishable on shipped data (nothing else is fixed in that window) and diverge only for a future --overlay entry in the same range, which the mechanism reading covers correctly and a two-saints special case would not. This project has already been bitten once (RG 16(a)) by a rule implemented against shipped data's coincidental shape rather than the rubric itself. Kernel stays rite-agnostic: Rite.t gains a fixed_key field (Date.t -> (int * int) option), the same seam easter already establishes, read only by Layer.on_date's FIXED half -- the movable half (Easter_offset/Nth_weekday) is untouched. Default is the identity mapping, an optional argument on on_date, so every existing caller and every rite that supplies nothing is byte-identical to before this field existed. Date.is_leap is exposed in date.mli (already existed in date.ml) so the rite reads the kernel's own single-sourced leap-year definition. The EF implementation lives in Rite_ef.Temporal_ef.bissextile_fixed_key, fully cited, wired into Rite_ef.context. Blast radius, measured over the full 1583-9999 domain (Calendar.year run twice per civil year, real fixed_key vs identity, every day diffed): all 2,041 leap years in the domain show a visible change for each saint; 6,983 individual liturgical days change total, zero unclassified, across four shapes (Matthias vacates 24 Feb in 1,803 years / occupies 25 Feb in 1,811; Gabriel vacates 27 Feb in 1,699 / occupies 28 Feb in 1,670). L3's own prior estimate (1,650 years, observed-outright only) is confirmed close on the same definition (1,677 measured); the broader observed-or- commemorated count is higher, not lower, showing the narrow estimate undercounted visible impact rather than overcounting it. The lectio differential (2005-2050 fixture) gains a new cited entry, C40 in data/ef/expected-divergences.sexp: lectio implements no such shift, so every leap year in its window now diverges on the two shifted days (21 rows, not the naive 44 -- the comparator never compares commemorations, so a side where the shifted saint has zero comparator-visible footprint on both engines produces no row). The LMS Ordo's 2023-2024 fixture -- the window L3 was originally found in -- now matches on the Creed comparison; its formulary-override bucket count is corrected 182->181 (24 February leaves the counted Proper population, becoming Own_slug-sourced). The missalemeum oracle fixtures (2026-2027, 2038, 2035) cover no leap year and are unaffected. L3 is closed: converted from an active allow-list record to a prose closure paragraph (L1's own precedent), citation preserved verbatim, fix and measured blast radius recorded. The id-list assertion narrows to [L4] alone, and the now-dead "2024-02-24" -> "L3" date mapping is removed. Six golden values pinned across four new test cases: Matthias in a leap year (both the vacated and occupied sides) and a common-year control; Gabriel likewise, deliberately choosing a leap year where he is admitted only as an ordinary commemoration rather than winning outright, a different shape from Matthias's. Mutation-tested: forcing fixed_key back to identity reddens exactly five test cases -- the differential's Layer C count-pin (C40 drops to 0 actual vs 21 expected), the LMS Ordo's Creed and formulary-bucket checks, and both new golden pins -- confirming the tests actually exercise the fix. Reverted; dune test, the exhaustive sweep, and make check are all green. 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. 2026-08-21T13:00:03Z 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. 2026-08-21T12:42:30Z 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. 2026-08-18T09:36:33Z Lukasz Kasprzak lukas@labunix.xyz 2026-08-18T09:36:33Z urn:sha1:0281a846ac7c22d22990a6664a37205930a94b7d RG 128, transcribed in the rules register since 2026-08-11, gives violet to "vigils of II and III class outside Paschaltide". The Vigil of the Assumption (14 August, II class) carried White and the Vigil of St Lawrence (9 August, III class) carried Red. Both are outside Paschaltide, so both are violet. The Ascension's vigil is untouched: it is the one II-class vigil inside Paschaltide and was already correctly white. The rule had been sitting in the register, disagreeing with the shipped data, since before the data was bootstrapped. It was invisible because colitur, lectio and missalemeum all carried the same two wrong colours -- colitur was bootstrapped from lectio, lectio's ini is generated from missalemeum, and missalemeum uses Divinum Officium's data files. Three sources agreeing is one source counted three times, and the differential and the oracle both went green on the shared error. It surfaced only against witnesses outside that tree: a published 1962 Ordo flagged the Assumption's, and O'Connell, The Celebration of Mass 4th ed. (1964), section 4(c) and footnote 169, gave the general rule and with it St Lawrence's, which the Ordo omits entirely. Two golden pins added, in years where each vigil is actually observed rather than impeded. The divergence this creates against every DO-lineage source is cited in both allow-lists: C37 (lectio, 77 rows -- 92 possible minus 15 where the vigil falls on a Sunday) and M29 (missalemeum, 3 rows in 2026-2027 and 2 in each of 2035 and 2038). Both gated on the exact slugs or dates and on colour alone, so any other divergence on those days would still surface. Also recorded, no code change: rose on Gaudete and Laetare stays. RG 131 is permissive ("adhiberi possunt") and the Ordo prints violet, so the colour field carries a permission rather than a requirement on those two Sundays a year -- a decided position now, not an unexamined one. 2026-08-18T09:26:04Z Lukasz Kasprzak lukas@labunix.xyz 2026-08-18T09:26:04Z urn:sha1:01219763c87c84175fcfa469882c6f30a56720d5 RG 128(b)'s own exception list, transcribed in the rules register and primary-source-verified since Task 16, excepts "Actione liturgica feria VI in Passione et Morte Domini usque ad Communionem exclusive" from the violet that otherwise runs from Septuagesima to the Easter Vigil. RG 132 assigns black there. The register recorded this as an acknowledged gap rather than a disputed reading -- the code comment beside the Holy Thursday exception says so in as many words -- and it is closed here. Found by two witnesses outside the Divinum Officium lineage that colitur, lectio and missalemeum all share: O'Connell, The Celebration of Mass, 4th ed. (1964), revised throughout to the Codex Rubricarum (1960) and the 1962 Missal, and a published 1962 Ordo. Both say black. So does missalemeum's own colour set, which orders the day "bv". The rubric is per-action ("usque ad Communionem exclusive") and the model emits one colour per day; black is the day's principal one, the same acknowledged limit RG 126's Palm Sunday blessing already carries. Blast radius: one day per year, colour only, across the whole 1583-9999 domain. Two golden pins re-pinned. Good Friday's 46 differential rows leave C23 for a new C36 gated on the exact triple [First_f; Gospel_f; Colour_f], so C23's own exact-pair gate still means what its note says for its remaining four days: 184 + 46 = 230, no residue, both counts from the comparator rather than hand-counted. 2026-08-17T15:22:43Z Lukasz Kasprzak lukas@labunix.xyz 2026-08-17T15:22:43Z urn:sha1:2b9f8133a22ce6dc309644a98bbe61507f574b38 Date_spec carried one variant, Fixed(month, day), and its own header said Sunday- and Easter-relative forms would arrive with the OF sanctoral. They arrive early because two things needed them at once: a user-supplied overlay carrying a local movable feast had no way to express "the first Sunday of October", and Rogation Wednesday's commemoration has been recorded as architecturally blocked since 2026-08-13. That blockage turns out to have been a premise, not a fact. The register concluded the Rogation "is not Commemoration_only sanctoral data by nature... it needs a genuinely THIRD kind of thing this architecture has no name for" -- but the reasoning rested on there being "no civil (month, day) pair to anchor a Fixed entry to". That is a statement about Date_spec's expressiveness. With Easter_offset the entity is ordinary sanctoral data, the identical shape Add major-litanies already ships, differing only in how the date is written. No third channel was needed. The register is corrected rather than left contradicting the code. Two variants: Easter_offset of int, and Nth_weekday of {month; nth; weekday} with negative nth counting from the end. Fixed's sexp representation is untouched, so all 327 sanctoral entries and the whole overlay parse unchanged. Both are re-validated in t_of_sexp through their smart constructors, extending the idiom Fixed already used -- the failure that guards against is invisible, a spec deserialising into something that silently never resolves and a celebration vanishing with no diagnostic. Easter is supplied by the rite, not computed in the kernel. Computus ships Gregorian and Julian both, and picking one here would hard-code a Roman assumption into rite-agnostic code and be silently wrong for a Julian-reckoning rite. Rite.t gains an easter field; Rite_ef supplies the Gregorian one. Layer keeps a split index. Fixed entries stay in the year-independent (month, day) table, which preserves the fast path and the "30 November counted twice in a 371-day span" behaviour validate.mli documents for St Andrew. Movable entries have no year-independent key by construction -- the same spec lands on a different (month, day) each year -- so they resolve per civil year into a rata-die table. index_by_date is removed rather than kept as an alias: two ways to index a layer, one of which silently ignores movable entries, is the trap this change exists to avoid. Two domain-edge defects, both found by the suite rather than reasoning. A liturgical year is Advent-anchored, so resolving civil year y names y +/- 1, and at the edges those are 1582 and 10000, which Computus correctly refuses by raising. The ceiling surfaced through the domain-ceiling test, the floor through `colitur day 1583` failing outright. Fixed once, in Layer.index, the single point that calls the rite's easter -- a clamp repeated per caller would have been two places to get wrong a third time. Rogation Wednesday: RG 87 assigns the Litaniae minores to the Monday, Tuesday AND Wednesday before Ascension (scan1:691); colitur built the first two from the start and never the third. RG 88 keeps it out of the Office, so the Ascension Vigil remains observed. RG 89 routes it through the Major Litanies' rules, but RG 109's closed list names only maiores, so by RG 107 it is an ORDINARY commemoration -- confirmed in the output, not assumed. Name from the Missal's own "feria IV" (scan1:20495-20497), violet to match the Monday and Tuesday offices. Blast radius, full 1583-9999 sweep against the pre-change binary: 2257 days, every one the same shape, zero unclassified, line counts equal both sides. The complement is the informative half -- in the other 6160 years the Rogation does not appear at all, because RG 111 admits one commemoration on a II-class day and an impeded feast takes it under RG 113, a Commemoration_only candidate having no row in RG 91's table. Both shapes are pinned. Allow-lists unmoved: layer 3 compares no commemorations and is blind by construction, and layer 4's 2026-2027 window has a competing feast on both Wednesdays, so the Rogation is capped out in exactly the years the oracle can see. C8 is unchanged, asserted by its own count pin. Not built: Sunday-relative specs, which nothing needs yet, and the --overlay plumbing that would let a user actually supply a local movable feast. Nth_weekday therefore ships with synthetic and property coverage only; inventing a shipped entry to exercise it would be fabricating calendar data. Register: section 6.10. 2026-08-17T12:56:46Z Lukasz Kasprzak lukas@labunix.xyz 2026-08-17T12:56:46Z urn:sha1:947cadfab527829f8e42a896339a0fa6c2e81ad9 Layers 2 and 5 for the reading citations, which until now had coverage from layers 3 and 4 only -- both oracle-bounded, at 2050 and 2027. test_validate.ml said so in its own words ("No fixture here exercises citations") and test_golden.ml's describe pinned twelve fields, none of them a citation. 358 tests -> 369, and 370 under the sweep. Layer 2 as two Validate checks rather than standalone QCheck properties, so they ride the existing prop_invariants and the exhaustive sweep instead of duplicating that machinery. "citations" asserts a day's parts, sorted, are exactly [First; Gospel] -- one condition carrying three invariants: zero or two but never one, nothing outside First and Gospel since the chants are deliberately unbuilt, and no part twice, which a bare cardinality test would miss. "citations-unresolved" is the separate coverage half: the chain fell through every step. Both are gated on the rite producing some citation somewhere, so a rite whose lectionary is not built is held to neither and the synthetic fixtures stay unaffected. The result over the whole domain: every day of every liturgical year 1583-9999 resolves exactly one Epistle and one Gospel. Mutation-proved live rather than merely silent -- treating a well-formed pair as malformed reddens the suite with real days showing [first,gospel]. citations-unresolved has no live witness at all, which is why test_validate.ml gains five fixtures driving both checks through a new ?readings override, including the gate itself. Layer 5 as six pins, one per chain step, so a regression names the step that broke. Every literal was read out of the scans before being compared with colitur, per that file's standing rule; scan lines are in each pin's comment. Two of the six cover step 4, and the plan's own dates for steps 1 and 4 were wrong: 2030-01-13 is a temporal day (Holy Family on the generic Sunday slug) and would not have exercised step 1, while 2038-03-08 is John of God, who has a full proper Mass and never routes through a Common -- so he becomes the step-1 pin instead. A separate formatter rather than widening describe: widening would invalidate all thirty existing literals at once and the only practical way back would be pasting in whatever colitur printed, which is what the file's header forbids. Restoring them honestly means hand-verifying thirty more Masses against the scans, a task of its own. Stated rather than hidden, and defensible because layer 2 now checks the shape of every day in every year, which is the breadth that widening would have bought. Two pins earned their keep immediately. Lent I Monday failed on "Ezek" against colitur's "Ezech" -- notation only, and colitur matches the Missal's own abbreviation; layer 3 normalises this away and cannot see it. The displaced-Sunday feria pins M26 shape 2(b)'s known-wrong walkback deliberately, labelled as such so a future fix fails loudly, and established two things M26 had not recorded: both parts come from the displacing feast, not only the Gospel it cites, and the reference carries a stray trailing period inherited through the bootstrap. Blast radius: zero. The CLI never calls Validate, no data file changed, and 20 years spanning 1583-9998 produce 7301 byte-identical lines between the pre-change binary and HEAD. Step 4's blind spot is now measured rather than argued. Corrupting the Common of Non-Virgins I's Epistle leaves layer 3 (16801 days) and layer 4 (730 days) both green, reddening only one unit test and one new pin. Both step-4 pins matched the scans on the first attempt -- the first independent confirmation that route has ever had. It narrows the gap without closing it: two of five Common-routed saints are witnessed, isidore-of-seville is not, and gregory-the-great and patrick are unreachable in any year 2005-2050. Register: section 6.7 addendum. validate.mli documents both new labels; liturgical_day.mli's "always empty until Plan 4" was outlived by the lectionary and is corrected.