From 12b97761019cfa02ca0da8a5fb50ef815d07685c Mon Sep 17 00:00:00 2001 From: Lukasz Kasprzak Date: Fri, 21 Aug 2026 14:42:30 +0200 Subject: feat(ef): implement RG 33's third omission trigger 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. --- lib/kernel/precedence.ml | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'lib/kernel/precedence.ml') diff --git a/lib/kernel/precedence.ml b/lib/kernel/precedence.ml index 2c55817..c207117 100644 --- a/lib/kernel/precedence.ml +++ b/lib/kernel/precedence.ml @@ -25,6 +25,12 @@ type ('s, 'r) rules = { has no [context] of its own to compute it with) -- see [resolve]'s own comment for why this is a KERNEL-level policy, not a rite- specific rule threaded in as data. *) + vigil_feast : 'r candidate -> Slug.t option; + (** RG 33's third omission trigger: the slug of the feast this candidate + is a vigil OF, when the rite subjects that vigil to omission; + [None] for every other candidate. See the .mli for the contract and + for why the kernel asks the rite to NAME the feast rather than infer + it. *) } type 'r resolution = { -- cgit v1.3