kernel(precedence): three RG-verified EF precedence bugs, found via oracle

Task 16's missalemeum oracle comparison (2026-2027) surfaced three
distinct precedence-engine bugs, each confirmed against the primary
1962 Missale Romanum text and cross-checked against the oracle:

1. RG 33 (vigil omission) was transcribed backwards. The primary text
   reads "Vigilia II AUT III classis penitus omittitur" (a II OR III
   class vigil is entirely omitted on any Sunday or I-class feast) --
   not "I aut II" as the register and this module's own rank check
   (Class1 || Class2) previously had it. I-class vigils (Nativity,
   Pentecost) can never actually lose in this engine (band always
   ranks them above anything that could coincide with their dates), so
   the Class1 half was dead code; the real bug was that Class3 (St
   Lawrence's vigil, the sole III-class vigil) was MISSING, so it fell
   through to an ordinary commemoration instead of RG 33's mandatory
   omission whenever 9 August landed on a Sunday.

2. RG 93/95/109/113 read together: an ordinary, non-privileged
   TEMPORAL-cycle office (a bog-standard green-season feria, a plain
   Advent/Lent Ember day, a Minor Rogation day) has no standing to be
   commemorated at all when impeded -- RG 109's six-item list is a
   CLOSED set of the only temporal circumstances that generate a
   commemoration, not a floor under which anything ordinary still
   gets one. The engine previously commemorated the losing feria
   itself in this situation; confirmed wrong against ~190 independent
   missalemeum days (2026-2027) showing zero commemorations for the
   exact shape. Vigils are explicitly excluded from this new rule --
   RG 31/32 give them their own "if impeded, commemorated" mandate,
   independent of RG 109's list.

3. RG 111(b)'s Sunday admission slot is restricted to "de festo II
   classis" -- a rank restriction, not merely the best available
   ordinary candidate. A III/IV-class ordinary saint competing for a
   II-class Sunday's single commemoration slot had no such restriction
   applied before; confirmed wrong via St Hyginus (11 Jan, Class3)
   losing to Holy Family, which missalemeum shows entirely displaced,
   never commemorated.

All three fixes are pure disposition/admission changes -- they never
touch band, so the observed day (season/slug/rank/colour) is
unaffected in every case; the lectio differential (which never
compares commemorations) stays green untouched. test_precedence_ef.ml
updated throughout: two previously-wrong test expectations corrected
(the RG33 III-class-vigil boundary row, the IV-class-feria totality
row), three privilege boundary rows sharpened from "commemorated but
unprivileged" to "omitted entirely" now that temporal+ordinary
means omission, and a new contrast row added to keep the SANCTORAL
side of rule 2 covered separately from the TEMPORAL side.

1 files changed, 76 insertions, 17 deletions

diff --git a/test/test_precedence_ef.ml b/test/test_precedence_ef.ml
index aa98686..2f08864 100644
--- a/test/test_precedence_ef.ml
+++ b/test/test_precedence_ef.ml
@@ -375,17 +375,34 @@ let disposition_cases =
       of_temporal (off 38),
       "Omit" );
     (* RG 33's own boundary, proved from both sides so the rule is shown to
-       gate on the WINNER too, not "any vigil is always omitted": *)
+       gate on the WINNER too, not "any vigil is always omitted": winner is
+       neither a Sunday nor I class, so RG 33's omission does not fire; the
+       vigil is temporal-origin ({!of_temporal}, the real Ascension Vigil)
+       and would otherwise land in Task 16's new "ordinary temporal loser ->
+       Omit" branch too (see the IV-class-feria row further down) -- this
+       row is what proves that branch's own [not (is_vigil ...)] guard: a
+       vigil, per RG 31's own text ("si impediuntur, commemorantur"), is
+       ALWAYS commemorated once RG 33 does not omit it outright, regardless
+       of RG 109's closed list. *)
     ( "RG33 boundary: vigil loses to an ordinary (non-Sunday, non-I-class) \
-       II-class day -> Commemorate, NOT Omit",
+       II-class day -> Commemorate, NOT Omit (RG31's own vigil mandate)",
       cand ~origin:P.Sanctoral ~rank:V.Class2 ~layer:PE.universal_layer "ef-some-other-feast",
       of_temporal (off 38),
       "Commemorate(Ordinary)" );
-    ( "RG33 boundary: a III-class vigil (outside RG33's I/II-class scope) \
-       loses to a Sunday -> Commemorate, NOT Omit",
+    (* CORRECTED 2026-08-12 (Task 16, primary-source-verified): the register
+       previously (mis-)transcribed RG 33 as covering only I/II-class
+       vigils, so this row's own title used to read "outside RG33's
+       I/II-class scope" and expect Commemorate. The primary text ("Vigilia
+       II AUT III classis penitus omittitur...") covers II OR III class --
+       St Lawrence's vigil (III class, RG 32) falling on ANY Sunday ("in
+       dominica quavis") is entirely omitted, exactly like a II-class vigil.
+       See {!PE.is_omissible_vigil}'s own comment for the full primary text
+       and the register correction. *)
+    ( "RG33 (corrected): a III-class vigil loses to a Sunday -> Omit, not \
+       Commemorate",
       an_ordinary_sunday,
       cand ~origin:P.Sanctoral ~rank:V.Class3 ~layer:PE.universal_layer "ef-lawrence-vigil",
-      "Commemorate(Ordinary)" );
+      "Omit" );
     (* Task 11, issue (a): [disposition]'s own [is_vigil] check (the RG 33
        omission test) is a SEPARATE call site from [band]'s -- both read the
        same private [is_vigil], but each needed its own witness, since a fix
@@ -424,16 +441,45 @@ let disposition_cases =
       cand ~origin:P.Sanctoral ~status:Cel.Commemoration_only ~layer:PE.universal_layer
         "ef-suppressed-vigil",
       "Commemorate(Privileged)" );
-    (* Totality: the lower ranks the RG 33/RG 95 branches never touch still
-       reach the RG 95 "commemorated or omitted" branch, not an
-       unhandled/exceptional case. *)
+    (* Totality (SANCTORAL side): the lower ranks the RG 33/RG 95/Task-16
+       branches never touch still reach the RG 95 "commemorated or omitted"
+       branch's [Commemorate] side, not an unhandled/exceptional case -- RG
+       111(c)/(d) admit an "ordinary" SAINT commemoration freely, with none
+       of RG 109's closed-list restriction the temporal branch below has. *)
     ( "III-class feast loses to a I-class day -> Commemorate",
       cand "ef-nativity",
       cand ~origin:P.Sanctoral ~rank:V.Class3 ~layer:PE.universal_layer "ef-some-saint-3",
       "Commemorate(Ordinary)" );
-    ( "IV-class feria loses to a II-class Sunday -> Commemorate",
+    (* Task 16 (primary-source-verified: RG 95 + RG 109's closed list + RG
+       113 -- see this branch's own comment in precedence_ef.ml for the full
+       three-text argument): an ORDINARY, non-privileged TEMPORAL-cycle
+       loser -- a bog-standard green-season feria of Time after Pentecost,
+       none of RG 109(a)-(f) -- has NO standing to be commemorated at all
+       when impeded; it is entirely omitted, not the "ordinary"
+       commemoration a losing SAINT would get (contrast the SANCTORAL row
+       immediately above, same rank, same kind of winner, opposite
+       [Commemorate]/[Omit] outcome -- the discriminating factor is
+       [origin], nothing else). Before this fix the engine wrongly
+       commemorated the losing feria itself here; confirmed wrong against
+       the missalemeum oracle (Task 16 report): every one of ~190
+       structurally identical days (an ordinary sanctoral feast impeding an
+       ordinary temporal feria, 2026-2027) shows zero commemorations in an
+       independent published EF calendar. *)
+    ( "TASK16: an ORDINARY temporal feria loses to a II-class Sunday -> \
+       Omit, not Commemorate (RG109's closed list; contrast the sanctoral \
+       row above)",
       an_ordinary_sunday,
       cand ~rank:V.Class4 "ef-time-after-pentecost-1-sat",
+      "Omit" );
+    (* Totality's other half: a SANCTORAL loser of the exact same rank as
+       the row above still reaches [Commemorate], proving the branch above
+       is gated on [origin] and not merely on rank -- without this row nothing
+       here would distinguish "temporal losers are omitted" from "IV-class
+       losers are omitted", which would be a much bigger (and wrong) claim. *)
+    ( "TASK16 contrast: a SANCTORAL IV-class loser still reaches \
+       Commemorate(Ordinary)",
+      an_ordinary_sunday,
+      cand ~origin:P.Sanctoral ~rank:V.Class4 ~layer:PE.universal_layer "ef-some-minor-saint",
       "Commemorate(Ordinary)" )
   ]
 
@@ -506,29 +552,42 @@ let privilege_cases =
        already used by the entry-18 [band] row above. Both sourced from
        [Temporal_ef.temporal]. If [privilege_of] relied on the season prefix
        alone without excluding Ember slugs, both would wrongly come back
-       [Privileged] -- the exact trap this pair of rows guards against. *)
+       [Privileged] -- the exact trap this pair of rows guards against.
+
+       CHANGED, Task 16: these used to expect [Commemorate(Ordinary)] --
+       "not privileged" originally meant "commemorated, but without RG 109's
+       higher liturgical honours". Now that a TEMPORAL-origin [Ordinary]
+       loser is Task 16's own [Omit] branch (see precedence_ef.ml), "not
+       privileged" for a temporal candidate means "not commemorable at all"
+       -- a sharper, more direct assertion of the same underlying
+       [privilege_of] classification, via the one vantage point available
+       on that private function. *)
     ( "boundary: an Advent Ember day is NOT privileged (only September is, \
-       RG109(d))",
+       RG109(d)) -- and being temporal+ordinary, TASK16 omits it entirely",
       cand "ef-nativity",
       of_temporal (mk 2026 12 16),
-      "Commemorate(Ordinary)" );
+      "Omit" );
     ( "boundary: a Lent Ember day is NOT privileged (only September is, \
-       RG109(d))",
+       RG109(d)) -- and being temporal+ordinary, TASK16 omits it entirely",
       cand "ef-nativity",
       of_temporal (off (-39)),
-      "Commemorate(Ordinary)" );
+      "Omit" );
     (* Negative, RG 109(f)'s own boundary: the Minor Litanies/Rogations
        (Monday/Tuesday before Ascension, RG 87 -- [Temporal_ef.temporal]
        DOES compute these, unlike the Major Litanies RG 109(f) actually
        names, see [privilege_of]'s own comment) must NOT be mistaken for the
        Major Rogations RG 109(f) privileges: RG 88 says the Minor Rogations
        change nothing in the Office at all, so nothing about them is
-       privileged either. *)
+       privileged either -- and (Task 16) being temporal+ordinary, a Minor
+       Rogation day impeded by a saint is now omitted outright, matching the
+       missalemeum oracle exactly (Task 16 report: 11 May 2026 and 12 May
+       2026, both Minor Rogation days impeded by a saint, show zero
+       commemoration of the Rogation in the independent oracle). *)
     ( "boundary: a Minor Rogation day is NOT privileged (RG109(f) names \
-       the Major Litanies, not these)",
+       the Major Litanies, not these) -- TASK16 omits it entirely",
       cand "ef-nativity",
       of_temporal (off 36),
-      "Commemorate(Ordinary)" )
+      "Omit" )
   ]
 
 (* Task 9: [PE.admit] -- RG 111's admission counts (register line 378),